JPH08211883A - Acoustic lens - Google Patents

Abstract

PURPOSE: To manufacture an inexpensive acoustic lens by a simple working. CONSTITUTION: A hole part 15 is formed on a first member 13, and a second member 14 consisting of the material in which an ultrasonic wave transmission speed is higher than that in the first member 13 is fitted and engaged to the hole part 15 of the first member 13, and an ultrasonic beam 12 is refracted by the difference in the ultrasonic speed between the first member 13 and the second 14, and the ultrasonic beam 12 is spread, and the inexpensive acoustic lens 11 is manufactured by the simple process, and the manufacturing time of the acoustic lens 11 is shortened, and the manufacturing cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic lens used in, for example, an ultrasonic imaging device for imaging the inside of a liquid in a pipe or a tank.

[0002]

2. Description of the Related Art FIG. 5 shows the overall structure of an ultrasonic imaging apparatus. As shown in FIG. 5, in the ultrasonic imaging apparatus, the acoustic lens 2 combined with the ultrasonic probe 1 is brought into close contact with the outer wall of the pipe 3, and the image of the object in the liquid 4 inside the pipe 3 is imaged. To convert. The ultrasonic beam 5 of the ultrasonic imaging device is expanded in the pipe 3 by the acoustic lens 2.

The structure of the conventional acoustic lens 2 will be described with reference to FIG. FIG. 6 shows an enlarged state of the main parts in FIG. The acoustic lens 2 includes the first member 6 having different ultrasonic sound speeds.
The ultrasonic probe 1 and the second member 7 are formed by forming a couplant layer by a couplant 8 and ultrasonically coupling the couplant layer.
Is composed of an ultrasonic transducer 9. A portion of the acoustic lens 2 where the first member 6 and the second member 7 contact each other has an arc shape.

[0004]

In the conventional acoustic lens 2 described above, as shown in FIG. 6, since the portions where the first member 6 and the second member 7 are in contact with each other are arcuate, they are separately provided. Although manufactured, it was very difficult to manufacture them by matching the curvatures of the arcs with each other. Therefore, there is a problem that a large amount of production cost and a lot of production time are required.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an acoustic lens which can be manufactured at low cost by simple processing.

[0006]

In order to achieve the above object, the structure of the present invention is an acoustic lens for refracting an ultrasonic beam of an ultrasonic imaging apparatus, wherein the first lens is made of a material having an arbitrary ultrasonic velocity. A hole is formed in the member, and a second member made of a material having an ultrasonic velocity different from that of the first member is used as the first member.
It is characterized in that it is closely engaged with the hole of the member.

[0007]

The acoustic lens is constructed by closely engaging the second member with the hole of the first member. First, the hole is expanded by heating the first member, and the round bar-shaped second member is fitted into the expanded hole. After fitting the second member, the hole is contracted by cooling, and the second member is tightly engaged with the hole by cold fitting. First
The ultrasonic beam is refracted by the difference in ultrasonic velocity between the member and the second member, and the ultrasonic beam is converged or diffused.

[0008]

FIG. 1 shows the configuration of an acoustic lens according to an embodiment of the present invention, and FIG. 2 shows the overall configuration of an ultrasonic imaging apparatus using the acoustic lens shown in FIG.

As shown in the figure, the acoustic lens 11 is for expanding the ultrasonic beam 12, and is composed of a first member 13 and a second member 14 having different ultrasonic sound speeds. A hole 15 is formed in the first member 13,
The round bar-shaped second member 14 is tightly engaged with the hole 15.
In order to expand the ultrasonic beam 12, it is formed of a material in which the sound velocity C2 of the ultrasonic waves of the second member 14 becomes faster than the sound velocity C1 of the ultrasonic waves of the first member 13 (C2> C1). Acoustic lens 11
In manufacturing, the first member 13 is first heated to expand the hole 15, and the expanded rod 15 is fitted with the round bar-shaped second member 14 by shrink fitting. Second member 14
After fitting, the hole 15 is contracted by cooling, and the second member 14 is tightly engaged with the hole 15 by cold fitting. This makes it possible to bring the first member 13 and the second member 14 into close contact with each other without using a couplant.

Ultrasonic waves are supplied to the acoustic lens 11 by an ultrasonic probe 16, and an ultrasonic transducer 17 is used for the ultrasonic probe 16. The ultrasonic imaging device brings the acoustic lens 11 combined with the ultrasonic probe 16 into close contact with the outer wall of the pipe 18 to image an object in the liquid 19 inside the pipe 18. The ultrasonic beam 12 of the ultrasonic imaging device is expanded in the pipe 18 by the acoustic lens 11 (see FIG. 2).

The above-mentioned curvature of the acoustic lens 11 has a hole 15
However, the hole 15 can be processed relatively easily and accurately, and the first member 13 and the second member 14 can be tightly engaged by shrink fitting and shrink fitting. As a result, a high degree of adhesion can be obtained, and ultrasonic waves can be propagated without using a couplant.

Further, as shown in FIG. 3, the second member 14
The refraction angle θ2a between the upper end of the (round bar) and the first member 13
The spread of is obtained. Here, due to the relationship of C2> C1 described above, the refraction angle θ2 of the first member 13> the incident angle θ1 to the first member 13, and the angle θ1 and the angle θ2 are expressed by the following formula 1. Can

[Equation 1] The refraction angle θ2a can be obtained by the following equation 2.

[Equation 2]

Further, as shown in FIG. 4, the second member 14
A refraction angle θ4a between the lower end of the (round bar) and the first member 13
The spread of is obtained. Here, because of the relationship of C2> C1 described above, the incident angle to the first member 13 (lower side) θ3> the refraction angle of the first member 13 (lower side) θ4, so the angle θ
3 and the angle θ4 can be expressed by the following equation 3,

(Equation 3) The refraction angle θ2a can be obtained by the following equation 4.

[Equation 4]

As a result, the ultrasonic wave output from the ultrasonic probe 16 can be generated as the ultrasonic beam 12 diffused into the liquid 19 through the outer wall of the pipe 18. Moreover, since the spread of the ultrasonic beam 12 can be obtained at the two positions of the upper end and the lower end of the second member 14, the lens effect can be increased without increasing the size.

Therefore, the acoustic lens 11 described above does not require accurate processing of curvature, and can be made the first by shrink fitting and shrink fitting.
Since the second member 14 can be tightly engaged with the hole 15 of the member 13, the acoustic lens 11 can be easily manufactured. Further, the divergence of the ultrasonic beam 12 necessary for ultrasonic imaging can be obtained at the upper end portion and the lower end portion of the second member 14 (round bar), and the diffused ultrasonic beam 12 can be generated. Therefore, the lens effect is increased without increasing the size of the acoustic lens 11, and the ultrasonic image is significantly improved.

[0016]

According to the acoustic lens of the present invention, a hole is formed in the first member, and a second member made of a material having a different ultrasonic velocity from that of the first member is tightly engaged with the hole of the first member. Since the ultrasonic beam is refracted and the ultrasonic beam is converged or diffused according to the difference in ultrasonic velocity between the first member and the second member, the acoustic lens can be manufactured at low cost by simple processing. . As a result, it is possible to reduce the manufacturing time and the manufacturing cost of the acoustic lens.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of an acoustic lens according to an embodiment of the present invention.

2 is an overall configuration diagram of an ultrasonic imaging apparatus using the acoustic lens shown in FIG.

FIG. 3 is an explanatory diagram of a lens effect.

FIG. 4 is an explanatory diagram of a lens effect.

FIG. 5 is an overall configuration diagram of an ultrasonic imaging apparatus using a conventional acoustic lens.

FIG. 6 is an enlarged view of a main part in FIG.

[Explanation of symbols]

 11 Acoustic Lens 12 Ultrasonic Beam 13 First Member 14 Second Member 15 Hole 16 Ultrasonic Probe 17 Ultrasonic Transducer 18 Piping 19 Liquid

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04R 1/34 330 A // G01N 29/06

Claims (1)

[Claims] 1. An acoustic lens for refracting an ultrasonic beam of an ultrasonic imaging apparatus, wherein a hole is formed in a first member made of a material having an arbitrary ultrasonic velocity, and the first member is an ultrasonic wave. An acoustic lens, characterized in that a second member made of a material having a different speed is tightly engaged with the hole of the first member.