JP3064183B2 - Ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe applied to an ultrasonic test for various industrial products.

[0002]

2. Description of the Related Art Conventional ultrasonic probes include a tire-type ultrasonic probe and a small-diameter roller-type ultrasonic probe disclosed in Japanese Patent Application No. 5-3221 by the present applicant.

As shown in FIGS. 5 and 6, the tire type ultrasonic probe is provided with a rubber tire 11 which rotates around a fixed shaft 16. A vibrator 13 attached to a fixed shaft 16 is arranged inside the rubber tire 11, and the inside is filled with the liquid medium 12. The ultrasonic wave 14 propagates through the test medium 10 through the liquid medium 12 and the tire 11 to detect a defect 15, and is used for automatic ultrasonic inspection of a rolled steel sheet. In this case, the same effect is obtained as when the probe directly contacts and follows the surface of the test body 10.

A small roller type ultrasonic probe is shown in FIG.
As shown in FIG. 4, a small-diameter roller-type plastic probe case 02 whose both ends are reduced by two steps and a vibrator 0 radially embedded in the center side surface of the probe case.
1, an oil pipe 09 inserted from one end of the probe case 02 and reaching the center side surface, a center portion and an intermediate portion of the probe case 02 are covered with a predetermined clearance, and an outer end surface of the probe case 02 is formed of the same. An elastic thin-walled tire 06 with a flange on the extension of the outer end surface of the intermediate portion, and a bearing inserted into both ends of the probe case 02 and arranged at a predetermined clearance on the outer end surface of the intermediate portion. Bearing 03 and sealing means 07 provided on the outer end surface at the central portion, the side surface at the middle portion, and the adjacent surface portion of bearing bearing 03 of probe case 02
a and 07b.

When this is used, a liquid medium is filled from the oil pipe 09, and then the inlet is plugged. Then, the transducer side of the probe case 02 is brought close to the device under test 10, and the thin tire 06 surface is applied as shown in FIG. Thereafter, ultrasonic waves are transmitted and received from the transducer 01 to perform ultrasonic flaw detection.

[0006]

The conventional tire-type ultrasonic probe described above has a structure in which the outer diameter of the tire is 50 to 200 mm larger than the diameter of the vibrator (about 20 mm). Therefore, when used in a narrow space, such as for flaw detection on the inner surface side of a small-diameter tube or inspection of the center hole of a rotor, these tire-type probes are often unsuitable because their outer dimensions are too large.

In such a case, flaw detection using a direct contact probe 17 has conventionally been performed as shown in FIGS. 6 and 7, but these direct contact probes 17 have a high speed scanning. The couplant 18 between the shoe 19 and the specimen 10
Cannot follow the scanning of the probe 17, and the stability of the reflected wave deteriorates, so that a good flaw detection result cannot be obtained. When the surface of the test piece was a curved surface, a shoe 19 corresponding to the curvature was required each time.

[0008] Since the tire-type probe contacts the test piece with the tire, when the rigidity of the tire is low, twisting occurs when scanning in a direction other than the rotation direction, and a good contact state cannot be maintained. Therefore, it is difficult to continuously scan spirally on a cylindrical surface such as the inner surface of the tube, and the inspection speed is reduced. Further, a thick tire is required to secure the rigidity of the tire, and the ultrasonic wave is significantly attenuated by the tire, and the defect detection ability is reduced.

In the case of a small roller type ultrasonic probe, it can be used even in a narrow space, and the thin rubber tire comes into contact with the surface of the test sample. For this reason, the ultrasonic waves from the vibrator are sequentially transmitted to the test object through the closely adhered solid, the thin liquid, the thin solid (thin tire), and the test object, so that the attenuation is small and the sensitivity is high. Can be detected.

However, the solid (thin tire) and the solid (inspected body) come into contact with each other on the inspected body, and there is a possibility that the propagation of ultrasonic waves may be hindered.

[0011]

The present invention employs the following means to solve the above-mentioned problems.

That is, as an ultrasonic probe, a small-diameter roller-type plastic probe case whose both ends are reduced by two steps is embedded in the center side surface of the probe case in the radial direction. A transducer, an oil pipe inserted from one end of the probe case and reaching the center side surface, and a center portion and an intermediate portion of the probe case covered with a predetermined clearance and an outer end surface of the probe case is A cylindrical elastic thin-walled tire with a brim extending over the outer end surface of the intermediate portion, and bearing bearings respectively inserted into both ends of the probe case and arranged at a predetermined clearance on the outer end surface of the intermediate portion When,
Sealing means is provided on the outer end surface at the central portion, the side surface of the intermediate portion, and the adjacent surface portion of the bearing bearing of the probe case, and a plurality of small holes are made in the thin tire made of the elastic body.

[0013]

In the above means, after filling the liquid medium from the oil pipe, the inlet is plugged or the liquid is continuously supplied through the oil pipe. Then, the transducer side of the probe case is brought close to the test object, and the thin tire surface is applied. Then, the liquid medium seeps out of the small hole, and the thin tire surface comes into close contact with the test object via the liquid film. Thereafter, ultrasonic waves are transmitted and received from the vibrator to perform ultrasonic inspection.

Thus, the ultrasonic wave from the vibrator is
Since the light passes through the closely adhered solid, the thin liquid, the thin solid (thin tire), the liquid film, and the test object sequentially into the test object, the attenuation is small and the detection with high sensitivity can be performed.

When scanning the probe case, that is, when moving between the objects to be inspected, the thin tire portion follows the rotation while the probe case remains fixed (or moves without rotating). Similarly, highly sensitive detection is possible. Also, even if the test object has a small diameter hole, the probe is a small diameter roller type and the vibrator is embedded in it, so it can be easily inserted into the hole and detection is possible. it can.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1 is a longitudinal sectional view, and FIG. 2 is a transverse sectional view.

The probe case 02 is made of a small-diameter roller type (diameter of about 30 mm) acrylic resin in which both ends are reduced by two steps. At this time, the length of the intermediate portion 02b is formed short. A vibrator 01 is embedded in the center side surface of the probe case 02 in a radial direction in a radial direction. As the vibrator 01, a split type having a frequency of 5 MHz capable of performing high-sensitivity flaw detection was used.
An acrylic resin 013 is filled in front of the vibrator 01,
The outer shape is in the initial state. The lead wire of the vibrator 01 passes through the probe case 02 and is connected to the probe cable 08 at one end. Further, the oil pipe 09 is inserted from the other end face, and the tip reaches the center side face.

A cylindrical butadiene rubber thin-walled rubber tire 06 that covers a central portion 02a and an intermediate portion 02b of the probe case 02 with predetermined clearances a and b is provided. On the surface of the thin rubber tire 06, small holes e are provided at predetermined intervals.
Has been opened. The outer end surface of the collar 06a of the thin rubber tire 06 is formed so as to extend on the outer end surface d of the intermediate portion 02b of the probe case 02.

Further, bearing bearings 03 having bol bearings 05 are inserted into both ends of the probe case 02, respectively. Then, it is set on the outer end face d of the intermediate portion 02b with a predetermined clearance c. Sealing plates 07a and 07b made of Teflon are provided at the clearances b and c for watertightness.

As described above, the oil (liquid medium) 012 is injected from the oil pipe 09 and filled in the clearance a.

An oil (liquid medium) 012 filled in the clearance a leaches a little from the small hole e to form an oil film f between the thin rubber tire 06 and the test piece 10 as shown in FIG. Performs the combining function. That is, the transmission of the ultrasonic wave is performed more favorably, and the detection sensitivity is improved. In order to maintain the internal pressure of the clearance a, an oil pipe 09 is required.
What is necessary is just to inject the oil (liquid medium) 012 more continuously.

The outer end of the probe case 02 is attached to a scanning jig, and the thin rubber tire 06 on the vibrator 01 side is brought into contact with the surface of the test piece 10 as shown in FIG. Then, ultrasonic waves are emitted from the vibrator 01 and the defect 15 is detected. When the probe case 02 moves, the thin rubber tire 06, the seal plates 07a and 07b, and the outer ring 03a of the bearing bearing 03 rotate and follow while the transducer 01 faces in the same direction.

In order to completely improve the ultrasonic wave propagation, the oil (liquid medium) 012 between the thin rubber tire 06 and the test piece 10 may be applied to the surface of the test piece 10 in advance, or another oil may be used. A pipe may be provided at a branch or the like and dropped. Alternatively, these means may be used without providing the small hole e.

As described above, the following features are exhibited. (1) Since the outer surface of the thin rubber tire 06 pressurized with the liquid medium closely follows the surface of the test piece 10 via an oil film,
Even when rotating at high speed, a constant contact state can be always maintained. (2) Since there is a solid medium and a liquid medium between the thin rubber tire 06 and the vibrator 01, even if the tire 06 rotates, propagation of the ultrasonic wave is not hindered. (3) Since the probe case 02 is formed of a fixed medium, the rigidity of the entire probe is extremely high even when the thin rubber tire 06 is used. (4) By attaching the ball bearings 03, it is possible to prevent the tire 06 from twisting even if the probe is subjected to both circumferential and axial movements, that is, so-called helical scanning, and to maintain a constant contact state. Can be. (5) Since the thin rubber tire 06 is used, the ultrasonic wave is less attenuated in the tire. Further, since a thin liquid medium is used (the solid medium has a better ultrasonic reciprocal transmissivity than the liquid medium), it is possible to use a high-frequency vibrator 01 of a split type or the like having a high frequency. (6) The outer diameter of the probe is reduced by the structure in which the vibrator 01 is embedded in the solid medium, and a small-diameter tube (inner diameter of about 100 m) is used.
m) can be applied to inner surface flaw detection and the like. (7) Since there is a liquid medium between the outer surface of the thin rubber tire 06 and the surface of the test specimen 10, the propagation of ultrasonic waves is improved,
In addition, the stability of reflection increases and the sensitivity improves.

[0025]

As described above, the present invention has the following effects. (1) Since the diameter of the probe case can be reduced, the probe case can be applied to a narrow portion which cannot be approached by a conventional tire type probe, and the flaw detection range is greatly expanded. (2) Automatic high-speed flaw detection becomes possible by continuous vertical and horizontal scanning of the probe, so that the cost and the construction period can be reduced by shortening the inspection time. (3) The durability of the vibrator is improved by employing the integrated vibrator embedded in the vibrator case, and a thin rubber tire can be easily replaced, so that an inexpensive probe can be provided. (4) By thinning the rubber tire and the liquid medium, the ultrasonic wave transmission performance is improved, and high-precision flaw detection can be performed. (5) Because of the bearing system, the stability and reproducibility of the ultrasonic reflected wave are significantly improved. (6) A small amount of oil (liquid medium) is leached from the small hole into the test piece, so that the propagation of ultrasonic waves is improved, the stability of reflected waves is increased, and a large amount of oil (liquid medium) and its supply device are used. It becomes unnecessary, and workability and work efficiency including pre-processing and post-processing are remarkably improved. Further, since the sealing performance of the sealing mechanism may be poor, it is inexpensive and the durability is improved.

[Brief description of the drawings]

FIG. 1 is a configuration sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1 of the embodiment.

FIG. 3 is a longitudinal sectional view of a first conventional example.

FIG. 4 is a sectional view taken along line BB of FIG. 3 of the conventional example.

FIG. 5 is a longitudinal sectional view of a second conventional example.

FIG. 6 is a cross-sectional view of FIG. 5 of the conventional example.

FIG. 7 is a longitudinal sectional view of a third conventional example.

FIG. 8 is a cross-sectional view of FIG. 7 of the conventional example.

[Description of Signs] 01 Transducer 02 Probe case 03 Ball bearing bearing 05 Ball bearing 06 Thin rubber tire 07a, 07b Seal plate 08 Probe cable 09 Oil piping e Fine hole

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Osamu Miyajima 2-3-30 Gamo, Joto-ku, Osaka-shi Eishin Chemical Co., Ltd. (56) References JP-A-64-75961 (JP, A) (58) Investigation Field (Int. Cl. ⁷ , DB name) G01N 29/00-29/28

Claims (1)

(57) [Claims] 1. A small-diameter roller-type plastic probe case whose both ends are reduced by two steps, a vibrator radially embedded in a central side surface of the probe case, and the probe The oil pipe inserted from one end of the slave case and reaching the center side surface, the center portion and the middle portion of the probe case are covered with a predetermined clearance, and the outer end surface is on the extension of the outer end surface of the middle portion of the probe case. A thin bearing made of an elastic body having a flange and a bearing bearing inserted into both ends of the probe case and arranged at a predetermined clearance on an outer end surface of an intermediate portion; and the probe case. An ultrasonic probe, comprising: sealing means provided at a central outer end face, an intermediate side face, and a proximity face portion of the bearing bearing, wherein a plurality of small holes are formed in the thin tire made of the elastic body. .