JPH109908A - Ultrasound transceiver - Google Patents

Abstract

(57) [Problem] To provide an inexpensive ultrasonic transmitting / receiving apparatus with an improved S / N ratio. SOLUTION: A first wall is provided opposite to a wall of a pipe through which a measurement fluid passes through the measurement fluid and is in contact with a vibrator.
An ultrasonic transmitter for transmitting ultrasonic waves into the measurement fluid by vibrating the diaphragm, and a second vibration being generated by vibrating the second diaphragm by the ultrasonic waves having propagated the measurement fluid. In an ultrasonic transmitting and receiving apparatus, in which a vibrator in contact with a plate and an ultrasonic receiver for receiving the ultrasonic wave, at least one of the first and second diaphragms has a surface shape formed of a set of chevron shapes. An ultrasonic transmission / reception device characterized by the above-mentioned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive ultrasonic transmitting / receiving apparatus having an improved S / N ratio.

[0002]

2. Description of the Related Art FIG. 4 is an explanatory view of the structure of a main part of a conventional example generally used in the prior art.
No.17. In the figure, FIG.
(B) is a transmission unit 1 or a reception unit 2 of a conventional ultrasonic transmission / reception device. As can be seen from FIG. 4, the shapes of the transmitting unit 1 and the receiving unit 2 are almost the same.

In the figure, 11 and 21 are ultrasonic vibrators,
12 and 22 are diaphragms, and 13 and 14 are terminals to which ultrasonic signals are supplied from an ultrasonic transmitter. Diaphragms 12, 22
Has only a surface shape as a curved surface or a shape including a curved surface. Reference numerals 23 and 24 are terminals for supplying the received ultrasonic signal to a subsequent detector or the like.

[0004] An ultrasonic transmitting and receiving apparatus comprising a transmitting section 1 and a receiving section 2 is used for an ultrasonic flowmeter, for example, as shown in FIG. FIG. 6 is a sectional view taken along line AA of FIG. As shown in FIG. 5, the transmission unit 1 is disposed on a wall surface of the pipeline 3.
The receiving unit 2 is arranged on the wall of the pipe 3 so as to face the transmitting unit 1.

In FIG. 6, when the measurement fluid 4 flows from above to below in FIG. 6, a well-known Karman vortex is generated alternately left and right downstream of a vortex generator 5 provided at the center of the pipe 3. It is known that the number of generated Karman vortices is proportional to the flow velocity of the measurement fluid.

[0006] Terminal 1 from an ultrasonic signal generator (not shown)
When the ultrasonic excitation signal is supplied to the transmission unit 1 from the transmission units 3 and 14, the ultrasonic vibrator 11 vibrates.
Is transmitted into the measuring fluid. The ultrasonic waves that have propagated through the measurement fluid and reached the receiving unit 2 are transmitted to the diaphragm 22 of the receiving unit 2.
Is vibrated and transmitted to the ultrasonic vibrator 21, and the ultrasonic vibrator 21 outputs this as an ultrasonic signal to a subsequent detector or the like (not shown).

When the ultrasonic wave encounters the Karman vortex while propagating through the measurement fluid, the ultrasonic wave undergoes a change in its phase. Therefore, the number of generated Karman vortices can be known from the output ultrasonic signal of the receiving unit 2 that receives the ultrasonic wave by detecting the change in the phase with a detector or the like, and the flow rate of the measurement fluid can be determined from this. Is required.

Thus, the diaphragms 12 and 22 have only the surface shape of a curved surface or a shape including a curved surface. Therefore,
The traveling direction of the ultrasonic wave transmitted from the diaphragm 12 into the measurement fluid is substantially the normal direction of each point on the curved surface where the ultrasonic wave is transmitted.

A part of the ultrasonic wave reaching the diaphragm 22 becomes a reflected wave, but most of the reflected ultrasonic wave is diffused in the fluid, and only a small part of the reflected wave returns to the diaphragm 12 again. It is. Even when the reflected wave that reaches the diaphragm 12 is further reflected by the diaphragm 12, most of the reflected waves have a finite reflection angle. And the one that interferes with is very small.

[0010]

In such an apparatus, at least one of the first and second diaphragms is formed into a curved surface or a shape including a curved surface, so that the transmitted wave and the reflected wave are formed. Interference can be prevented. However, in order to form a curved surface or a shape including a curved surface, the surface protrudes from the tube wall.

For this reason, the flow of the measuring fluid is obstructed. Further, since it is necessary to form the curved surface so as to prevent interference, it is difficult to determine the curved surface shape, and the manufacturing cost is increased.

The present invention solves this problem. An object of the present invention is to provide an inexpensive ultrasonic transmission / reception apparatus with an improved S / N ratio.

[0013]

In order to achieve the above object, the present invention provides a method in which a first fluid is provided on a wall of a conduit through which a measuring fluid passes through the first fluid, the first fluid being provided in contact with the vibrator.
An ultrasonic transmitter for transmitting ultrasonic waves into the measurement fluid by vibrating the diaphragm, and a second vibration being generated by vibrating the second diaphragm by the ultrasonic waves having propagated the measurement fluid. In an ultrasonic transmitting and receiving apparatus, in which a vibrator in contact with a plate and an ultrasonic receiver for receiving the ultrasonic wave, at least one of the first and second diaphragms has a surface shape formed of a set of chevron shapes. An ultrasonic transmitting / receiving apparatus characterized by the above features.

[0014]

In the above arrangement, when an ultrasonic excitation signal is supplied from an ultrasonic signal generator (not shown) to the transmitting section, the ultrasonic vibrator vibrates, and this vibration is generated in the measurement fluid by the diaphragm. Sent. The ultrasonic wave that propagates in the measurement fluid and changes in phase due to the Karman vortex and reaches the receiving unit vibrates the diaphragm of the receiving unit and transmits it to the ultrasonic vibrator,
Further, the ultrasonic vibrator outputs this as an ultrasonic signal to a subsequent detector or the like (not shown).

Therefore, the number of generated Karman vortices can be determined by detecting the change in phase by a detector or the like from the output ultrasonic signal of the receiving unit that receives the ultrasonic waves, and thereby the measurement fluid can be measured. Is determined.

Thus, the diaphragm has a surface shape formed of a set of chevron shapes. Therefore, the traveling direction of the ultrasonic wave transmitted from the diaphragm into the measurement fluid is substantially the normal direction of each point on the chevron where the ultrasonic wave is transmitted. A part of the ultrasonic wave that reaches the diaphragm becomes a reflected wave, but most of the reflected ultrasonic wave is diffused in the fluid, and a small part of the reflected wave returns to the diaphragm again.

Even when the reflected wave reaching the diaphragm is further reflected by the diaphragm, most of the reflected waves have a finite reflection angle. And the one that interferes with is very small. Less than,
This will be described in detail based on an embodiment.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a main part of an embodiment of the present invention. In the figure, the configuration of the same symbol as FIG. 4 represents the same function. Hereinafter, only differences from FIG. 4 will be described.

Reference numerals 61 and 71 denote diaphragms configured so that the surface shape becomes a continuous shape of a triangular roof. FIG. 2 is a perspective view of the diaphragms 61 and 71.

In the above arrangement, when an ultrasonic excitation signal is supplied from an ultrasonic signal generator (not shown) to the transmitting section 6, the ultrasonic vibrator 11 vibrates.
1 transmitted into the measuring fluid.

The ultrasonic wave that propagates through the measuring fluid 4 and changes its phase due to the Karman vortex and reaches the receiving unit 7 is
The vibrating plate 71 of the receiving unit 7 is vibrated and transmitted to the ultrasonic vibrator 21, and the ultrasonic vibrator 21 outputs this as an ultrasonic signal to a subsequent detector or the like (not shown).

Accordingly, the number of generated Karman vortices can be known by detecting the change in phase from the output ultrasonic signal of the receiving unit 7 for receiving the ultrasonic wave by a detector or the like, and the measurement can be performed from this. The flow rate of the fluid is determined. The diaphragms 61 and 71 have a surface shape of a continuous shape of a triangular roof.

Therefore, the traveling direction of the ultrasonic wave transmitted from the diaphragm 61 into the measurement fluid is substantially the normal direction of each point on the triangle where the ultrasonic wave is transmitted. A part of the ultrasonic wave that reaches the diaphragm 71 becomes a reflected wave, but most of the reflected ultrasonic wave is diffused in the fluid, and only a small part of the reflected wave returns to the diaphragm 61 again.

The reflected wave arriving at the diaphragm 61 is
Even when the light is further reflected by 1, most of them have a finite reflection angle, and therefore, only a few of them directly interfere with the ultrasonic waves transmitted from the diaphragm 61.

As a result, the diaphragms 61 and 71 are formed so that the surface shape is a continuous shape of a triangular roof, so that the surface can be made flat and thin as a whole. Therefore, there is no fear that the surface protrudes from the wall surface of the pipe 3. For this reason, it is possible to obtain an ultrasonic transmission / reception device that is particularly suitable for sanitary use without obstructing the flow of the measurement fluid.

Further, since it is sufficient that the triangular roof has a continuous shape, it is easy to manufacture, and it is not necessary to make it precisely. Therefore, the manufacturing cost can be reduced. In addition, by devising the angle of the triangle, it is possible to uniformly diverge in a certain direction.

FIG. 3 is an explanatory diagram of a main part configuration of another embodiment of the present invention. In the present embodiment, the surface shapes of the diaphragms 81 and 91 are formed as a triangular pyramid.

[0028]

As described in detail above, the present invention provides
Since the surface shape of the diaphragm is configured to be a shape composed of a set of chevron shapes, the surface can be made flat and thin as a whole.

Therefore, there is no possibility that the surface protrudes from the wall surface of the pipe. For this reason, it is possible to obtain an ultrasonic transmission / reception device that is particularly suitable for sanitary use without obstructing the flow of the measurement fluid. In addition, since it is sufficient that the shape is an aggregate shape of a chevron, it is easy to manufacture, and it is not necessary to make it precisely.

Therefore, the manufacturing cost can be reduced. In addition, by devising the angle of the chevron, it is possible to uniformly diverge in a certain direction.

Therefore, according to the present invention, it is possible to realize an inexpensive ultrasonic transmitting / receiving apparatus with an improved S / N ratio.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of a main part of FIG.

FIG. 3 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a configuration of a conventional example generally used in the related art.

FIG. 5 is an explanatory diagram of a usage example of FIG. 1;

FIG. 6 is an operation explanatory diagram of FIG. 5;

[Explanation of symbols]

 6 Transmitter 7 Receiver 11 Ultrasonic vibrator 13 terminal 14 terminal 21 Ultrasonic vibrator 23 terminal 24 terminal 61 diaphragm 71 diaphragm 81 diaphragm 91 diaphragm

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Fujita 2-9-132 Nakamachi, Musashino City, Tokyo Inside Yokogawa Electric Corporation

Claims (1)

[Claims] An ultrasonic wave is introduced into a measurement fluid by vibrating a first diaphragm which is provided on a wall of a pipe through which the measurement fluid passes through the measurement fluid and is in contact with a vibrator. An ultrasonic transmitter for transmitting, and an ultrasonic receiver for causing a vibrator in contact with the second diaphragm to receive the ultrasonic wave by vibrating the second diaphragm with the ultrasonic wave that has propagated the measurement fluid An ultrasonic transmission / reception device comprising: an ultrasonic transmission / reception device comprising: a surface shape of at least one of the first and second diaphragms is a shape formed by a set of chevron shapes;