JPS62278445A - Multiple ultrasonic probe - Google Patents

Abstract

PURPOSE:To achieve a higher detecting capacity, by arranging a plurality of external ultrasonic vibrators in the perimeter of a center ultrasonic vibrator to allow the admission of ultrasonic waves into a defect of an object to be inspected from more than one directions. CONSTITUTION:A center ultrasonic vibrator 2 is arranged downward at the center of a cylindrical case 1 with the open bottom. External ultrasonic vibrators 3a-3d are mounted in the perimeter of the vibrator 2 and in the direction divided by 90 through wedges 4a-4d at such an attitude as to face the center line O of the vibrator 2 at the same angle separately. The wedges 4a-4d are isolated with an acoustic shielding plate 5. Ultrasonic waves generated from the vibrators 3a-3d are made to cross with the center liner O right below the vibrator 2 passing through the wedges 4a-4d, reflected from any defect near the crossing points and the reflected waves are received with the vibrator 2 to detect it. Thus, ultrasonic waves for detecting flaws can be transmitted to a defect from four equally divided directions thereby enabling detection of a flaw in an object to the inspected regardless of the shape thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Detailed Description of the Invention Field of Industrial Application The present invention relates to a multi-ultrasonic probe for detecting welding defects and internal defects in cast iron.

BACKGROUND OF THE INVENTION Various types of ultrasonic flaw detection devices have already been proposed that use ultrasonic waves to detect weld defects in weld lines and defects inside castings. 1
There is one shown in No. 38455.

As shown in FIG. 810 and FIG. ) ultrasonic transducer.

The ultrasonic waves were radiated in only one direction (180°).

Problems to be Solved by the Invention Since the above-mentioned conventional multi-ultrasonic probe emits ultrasonic waves in one direction (180°), the defect may be detected depending on the shape and direction of the defect in the object to be tested. The problem was that I couldn't do it.

For example, as shown in Fig. 12, if the defect C is long and thin, the defect C can be detected if the ultrasonic wave is incident from the direction perpendicular to the defect C, as shown by the arrows d, d-, in the figure. , arrow t1. As shown in ε2, when ultrasonic waves were incident on the defect C from the longitudinal direction, this could not be detected in some cases.

Means and Effects for Solving the Problems The present invention has been made in view of the above-mentioned problems, and therefore provides a device that can significantly improve detection power compared to conventional multi-ultrasonic probes. The configuration is a multi-ultrasonic probe in which outer ultrasonic transducers are arranged in pairs on both sides of a central ultrasonic transducer, and multiple pairs of outer ultrasonic transducers are provided over 360 degrees around the central ultrasonic transducer. The structure is such that ultrasonic waves are incident on the defect of the object to be detected from two or more directions.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 9.

In the figure, reference numeral 1 denotes a cylindrical case with an opening at the bottom, and a central ultrasonic transducer 2 is provided in the center of the case 1 so as to face downward. Also, around this central ultrasonic transducer 2 and in the 90' division direction, an outer ultrasonic transducer 3α,
3b, 3c.

3cL is the center line O of the central ultrasonic transducer 2, respectively.
Wedge 4 so that it faces at the same angle as the
The respective wedges 46 to 4d to which the above-mentioned outer ultrasonic transducers 3a to 3d attached to α+4h+4c and 4rL are attached are isolated by the acoustic isolation plate 5.

Note that the wedges 4α to 4d may be integrally formed without necessarily being divided according to the respective outer ultrasonic transducers 3α to 3d. In this case, a cylindrical acoustic shielding plate is provided around the central ultrasonic transducer 2.

In FIG. 2, the sound absorbing material 7 covers the upper surfaces of the six outer ultrasonic transducers 3α to 3d, and 7 is a high damping material filled in the case 1.

The central and outer ultrasonic transducers 2, 3cL to 3d are connected to the main body of the flaw detection apparatus via lead wires and cables (not shown), respectively.

Next, the flaw detection action will be explained. First, place the lower surface of the contact on the upper surface of the object to be tested, and
A 5MH2 ultrasonic signal is applied to generate sound waves.

The sound waves generated by each vibrator 3G to 3d are wedge 4α
Center 1 directly below the central ultrasonic transducer 2 through ~4d! O
If there is a defect near this intersection, it will be reflected to it. This reflected wave is received by the central ultrasonic transducer 2 and sent as a signal to a flaw detector, which detects the defect.

At this time, since the ultrasonic waves for flaw detection are emitted equally from four directions to the defect, it is detected regardless of the shape of the defect within the object to be tested.

Experimental example When there is a long and thin defect 104 in the casting 10 shown in Fig. 3, the flaw detection waveform of the defect echo when a conventional two-way ultrasonic contactor is set in the longitudinal direction A is shown in Fig. 4. Similarly, when the ultrasonic contactor shown in the above embodiment of the present invention is set with one of the ultrasonic transducers in the A direction, the defect echo waveform is as shown in FIG. It can be seen that the peaks x and x' of the waveforms in both figures indicate the presence of a defective portion, and in the case of the same defect, the ultrasonic probe according to the present invention has superior detection power.

In the above embodiment, an example was shown in which the outer ultrasonic transducers were arranged at four locations in the 90' direction with respect to the central ultrasonic transducer, but this may also be arranged at g locations in the 45° direction. A plurality of pairs of transducers are provided at equal intervals around the central ultrasonic transducer.

In the above-mentioned ultrasonic probe, the detection depth is roughly determined by the angle of the hood, and moreover, it can detect only one spot in the depth direction.To improve this, it is configured as shown in Figure 6. Good too.

That is, on both sides of the central ultrasonic transducer 110, there are two pairs of outer ultrasonic transducers 12 with different wedge angles of 70° and 45°.
cs, +2A and +3α, +3b are provided. Note that there may be two or more pairs in the same direction.

Experimental Example As shown in Fig. 7, the test piece 14 has a conventional multi-ultrasonic probe with a depth of focus of 5, and horizontal holes +54.15b and +5 at positions 15 m and 25 mm from the deeper surface.
0, and compared detection using a conventional multi-ultrasonic transducer and the above-mentioned multifocal type probe.

As a result, as shown in Figure 8, the defect echo of the conventional type detected only the defect due to the horizontal hole 5a located at depth 5, whereas the multifocal type described above detected only the defect due to the horizontal hole 5a located at depth 5. As shown, defects caused by three horizontal holes 5α and 54.5c were detected.

Effects of the Invention According to the present invention, since a plurality of pairs of outer ultrasonic transducers 3a to 3d are arranged around the center ultrasonic transducer 2, ultrasonic waves can be generated from the outer ultrasonic transducers 3a to 3d. At this time, the central ultrasonic transducer 2 receives the ultrasonic waves from 360° directions, making it possible to significantly improve detection power compared to conventional multi-ultrasonic probes. .

[Brief explanation of the drawing]

1 to 9 schematically show an embodiment of the present invention, with FIG. 1 being a bottom view and FIG. 2 being A-A@ and B of FIG.
-A cross-sectional view along line B, Figure 3 is an explanatory diagram showing defects in the object to be tested, Figures 4 and 5 are diagrams showing echoes of the defect shown in Figure g3, and Figure 6 is a diagram showing other implementations. An explanatory diagram showing an example, FIG. 7 is a perspective view showing the other side of the object to be tested, FIGS. 8 and 9 are diagrams showing defect detection echoes in other embodiments, and FIGS. 10 to 12 are This shows a conventional example, and Fig. 10 is a cross-sectional view;
FIG. 1 is a bottom view, and FIG. 12 is an explanatory diagram showing the detection direction for long and narrow defects. 2 is the central ultrasonic transducer, 3cL, 3h, 3c. 3d is the outer ultrasonic transducer.

Claims (1)

[Claims] In a multi-ultrasonic probe in which outer ultrasonic transducers are arranged in pairs on both sides of a central ultrasonic transducer, outer ultrasonic transducers 3a, 3b, 3c, and 3d are placed around the central ultrasonic transducer 2.
A multi-ultrasonic probe characterized in that a plurality of pairs are provided over 60 degrees.