JPS63259460A - Ultrasonic probe apparatus - Google Patents

Abstract

PURPOSE:To improve the SN ratio in ultrasonic flaw detection, by arranging a partition made of a resin, rubber or the like between an ultrasonic probe and material to be inspected to cut off side lobe alone instead of a main lobe. CONSTITUTION:An ultrasonic wave from a vibrator 2 of an ultrasonic probe 1 is made incident into a cylindrical material 7 to be inspected. A main lobe 5 of the ultrasonic wave is incident into the material 7 being inspected at a specified angle via an acoustically coupling material 4 and propagates as trans verse ultrasonic wave. Here, a partition 9 made of a resin, rubber or the like is provided on the rear side with respect to the direction of propagation of the ultrasonic wave and cuts off a side lobe 6 alone instead of the main lobe 5. As a result, the side lobe 6 is absorbed by the partition 9 and reflected on the acoustically coupling material 4, hence failing to reach the material 7 being inspected. Thus, in a flaw detection waveform figure, there is no noise generated between first and second surface echoes S1 and S2. The arrangement of the partition can improve the SN ratio in the ultrasonic flaw detection.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is an ultrasonic probe that detects defects, inclusions, etc. existing under the skin of bars, rice grains, etc. by ultrasonic angle flaw detection. This is related to child devices.

[Conventional technology]

Figure #2 is a diagram showing a conventional ultrasonic probe device shown, for example, in the ultrasonic flaw detection method (1972, published by Nikkan Kogyo Shimbun).

! Figure 2 (←) is a sectional view of the ultrasonic probe device, and Figure 2 (←) is a flaw detection waveform diagram using a conventional ultrasonic probe device.

In the figure, (1) is an ultrasonic probe, (2) is a transducer that transmits and receives ultrasonic waves, (3) is a backing material, (41 is an acoustic coupling material made of water, oil, etc.), and (5) is an ultrasonic wave probe. main lobe.

(61 is the ultrasonic side rope, (7) is the material to be tested, α is the material to be tested (the incident angle of the ultrasound to 71, C is the material to be tested (
7, T is the transmission pulse, 81 is the surface echo of the first flute, 82 is the surface echo of the second tilt, B is the side rope (bottom echo by 61, (81 is the flaw detection gate).

The conventional ultrasonic probe device is configured as described above in order to perform flaw detection on the subcutaneous part of the material to be inspected (7) by minimizing the undetected area as much as possible.

The angle angle flaw detection method is generally used. In the angle angle flaw detection method, when an ultrasonic wave is incident at a predetermined angle α to the normal line passing through the center C of the test material (71), a refraction angle corresponding to the incident angle α is given according to Snell's law. It is something.

There are a main lobe (5) and a side lobe (61) in the ultrasonic beam emitted from the sensor (2), and in normal ultrasonic flaw detection, the main lobe (5) is evaluated.

In particular, automatic ultrasonic flaw detection equipment uses a non-contact method to conduct sound vIFB composite material (4) f between the surface of the test material (71) and the ultrasonic probe device.
There is a condition in which the side lobe (6) component generated from the vibrator (21) is incident almost perpendicularly toward the center C of the test material (2).

The above conditions become more pronounced as the outer dimensions of the test material (7) become smaller.

[Problem that the invention seeks to solve]

If the incident amount is almost perpendicular to the center C of the side lobe (the 61st component is the surface of the test material) as shown in the above example, it will propagate through the test material (2) as a longitudinal ultrasonic wave. - In an ultrasonic probe device in which the incident angle α is set so that the main lobe (5) propagates through the test material (71) as a transverse wave, the entire time after the transmitted pulse T is The propagation time of the ultrasonic wave is set at the transverse sound velocity of material (71).

Or because it is calculated, the first surface echo 8
A flaw detection gate (8
Even if 1 is set as the shear wave sound velocity time, the longitudinal wave ultrasound due to the side lobe (6) component will bounce as bottom echo B, and the shear wave ultrasound from the main lobe (5) will bounce once to the side of the test material (7). Since it occurs in a slightly shorter period of time, it is always read into the flaw detection gate (81) as a noise component, causing the problem of deteriorating the sly ratio.

This invention was made in order to solve the above problem, and it is possible to prevent the sidelobe components from entering the specimen material by S/
The purpose is to obtain an ultrasonic probe device with a good N ratio.

Means for Solving Problem c] The ultrasonic probe device according to the present invention has a material having relatively low acoustic impedance such as plastic or rubber material on the rear surface with respect to the propagation direction of the ultrasonic wave. consisting of shiki, be,
Yr, main lobe is not blocked, only side lobe is f! It is installed in the position where it is cut off.

[Effect]

In this invention, a barrier plate is attached to the rear surface in the propagation direction of the ultrasonic wave, and the barrier plate is fixed at a position such that it blocks only the side lobes without blocking the main lobe. Therefore, the longitudinal ultrasonic wave component that is incident almost perpendicularly toward the center of the test material no longer enters the test material. therefore.

Also in the flaw detection waveform diagram, an ultrasonic probe device can be obtained in which noise components due to longitudinal ultrasonic waves are not generated during the flaw detection gate.

〔Example〕

FIG. 1 is a diagram showing an ultrasonic probe device 2 showing one embodiment of the present invention.

Figure 1 (a) is a cross-sectional view of the ultrasonic probe device;
)) is a flaw detection waveform diagram by the ultrasonic probe device of the present invention.

In the figure, (11 is an ultrasonic probe, (2) is a transducer, (
3I is the backing material, (4) is the acoustic coupling material, (5) is the main lobe, (6) is the side lobe, (7I is the test material,
(81 is a flaw detection gate, (91 is a shield plate made of plastic, rubber, etc. according to the invention of Keko), α is the ultrasonic incident angle on the test material (71, C is the center of the test material + 71, T is the transmission pulse .

81 is the first surface echo, and s2 is the 12th surface echo.

In the ultrasonic probe device configured as above,
The main lobe of the ultrasound emitted from the transducer (2+)
) and the side lobe (6) propagate to the surface of the test material (71) via the acoustic coupling material (4).At this time,
The main lobe (
51J'ig is not cut off, but only the side lobe 161 is cut off because the threshold C& (91f is provided).

The main lobe (5) enters the test material (7) at a predetermined angle and propagates as a transverse ultrasonic wave. On the other hand, the side lobe (6) reaches the barrier plate (9) in the acoustic coupling material (4) and is partially absorbed into the barrier plate 19), but? ! !
Tondoke acoustic coupling material (4! Because it is reflected by the test material (
7) The longitudinal ultrasonic wave propagating toward the center C no longer exists. As a result, in the flaw detection waveform diagram, no noise echo due to longitudinal ultrasonic waves is generated between the first surface echo 81 and the second surface echo S2 of the chick9. The distance between the device (1) and the surface of the material to be tested (7) is determined by the second surface echo 6 inside the flaw detection gate C8).
2), and the ultrasonic refraction angle in the commonly used test material (7) is 45°.
A distance approximately equal to the external dimensions of O and SX is required.

〔Effect of the invention〕

As explained above, the present invention provides an ultrasonic probe device that obliquely injects ultrasonic waves in the circumferential direction of a test material having a cylindrical outer shape, in an acoustic coupling material, With respect to the propagation direction of the M sound wave, if a shield made of plastic, rubber, etc. is installed on the rear surface in a position that does not block the main lobe but only connects one side rope, the side lobe It is possible to prevent the light from entering perpendicularly toward the center of the specimen.

As a result, since no longitudinal ultrasonic waves are generated in the test material, no echoes that become noise components are generated between the first surface echo 81 and the second surface echo S2, and the S/N ratio This has the effect of supplying a good ultrasonic probe device.

[Brief explanation of drawings]

Fig. 1(a) is a cross-sectional view of the ultrasonic probe device according to the present invention, Fig. 1) is a flaw detection waveform diagram by the ultrasonic probe device according to the present invention, and Fig. 2(a) is a cross-sectional view of the ultrasonic probe device according to the present invention. The cross-sectional view of the sonic probe device, Fig. 2(b), is a flaw detection waveform chart by a conventional ultrasonic probe device. In the figure, (1) is an ultrasonic probe, (21 is a transducer, (
41 is the acoustic coupling material, (5) is the main lobe of the ultrasonic wave, (
6) is the ultrasonic sidelobe, (7I is the test material, (9)
It is a Hashiki υ board. In addition, are the same symbols in each figure the same or equivalent parts? It shows. l super + 汲琳琳÷ 1st! 10 4 Thoughts 1: Bath Nucleus” -
m-Human 1 Figure 2 (α) GoT]-

Claims (1)

[Claims] The outer shape of the test material is cylindrical, and the ultrasonic wave is obliquely incident in the circumferential direction of the test material, and there is a space between the test material and the ultrasonic probe of approximately 0.5 x external shape. In an ultrasonic probe device that performs ultrasonic angle flaw detection by providing a distance space of about the same size and filling the distance space with an acoustic coupling material such as water or oil, with respect to the propagation direction of the ultrasonic wave, An ultrasonic probe device characterized in that a partition plate made of plastic, rubber, etc. is attached to the rear surface in a position that blocks only the side lobes without blocking the main lobes.