JPS59128444A - Electromagnetic flaw detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to non-destructive testing equipment for materials and products, and more particularly to electromagnetic flaw detectors.

The present invention is most usefully used for inspecting various parts, such as shafts and disk 1 blades attached to aircraft engine turbines, ie, detecting surface defects such as large, medium, and small scratches.

As is known, it includes a self-excited oscillator, one of which inductance coils acts as an electromagnetic transducer, and further includes components electrically connected to the above, in which a detection There are electromagnetic flaw detectors including elements, signal limiters and indicators (USSR Inventor's Certificate No. 657,328, CL, G
Ol N 27/86.

(Refer to publication April 15, 1979).

Known detectors designed for inspection of rolled materials have low sensitivity and only detect defects such as large scratches.

It also includes a self-excited oscillator, one of which has an inductance coil that acts as an electromagnetic transducer, and further includes means connected in series with the above to serve to detect defects in the inspected part. Electromagnetic flaw detectors are known (Dorofeyev Ken A.L., Kazamanov N.G. "Electromagnetic Inspection" Moscow,
(see Masinstronie-Verlag, 1980, pp. 98-103).

The inspection reliability of the flaw detector mentioned above is determined by the possible tilting, dislocation, and
and movement relative to the edges of the article.

The sensitivity of the above detector designed for the purpose mentioned above is low (
The depth and length of detectable surface defects are each 0.3~
0.5211' and 1.5 tm), its inspection reliability is not high for inspection of components such as aircraft engine turbine blades.

To be able to inspect parts made of different metals, a set of different electromagnetic transducers is generally required.

One object of the present invention is to provide a flaw detector with substantially increased sensitivity.

Another object of the invention is that in one electromagnetic transducer,
For these and other purposes, an electromagnetic flaw detector comprising a self-excited oscillator, one of which has an inductance The coil operates as an electromagnetic transducer and further includes means connected in series thereto to serve for detecting defects in the component under test; and a tuned amplifier connected to the input of the means for detecting defects in the test component, wherein one element of the oscillator circuit in the tuned amplifier operates as a sensitivity adjustment controller for the flaw detector. An electromagnetic flaw detector is proposed here.

The sensitivity of the electromagnetic flaw detector designed as described above has been improved to the level necessary to detect small scratches on the surface of the inspected parts, and it is
This can be improved by using two electromagnetic transducers.

These and other objects and advantages of the present invention will become more fully apparent from the following description of the preferred embodiments and the accompanying drawings.

The electromagnetic flaw detector according to the invention comprises series connected elements, among which a self-excited oscillator 1 (FIG. 1);
One inductance coil therein acts as an electromagnetic transducer 2 located above the test part (not shown) and also includes a follower 3, further connected to the input of means 5 for detecting defects in the test part. A tuned amplifier 4 is included.

Referring to FIG. 2, the tuned amplifier 4 includes an element 6 which acts as a suitable amplifier and is connected through an oscillator circuit 7 to a power supply (shown in the figure in the form of a terminal for simplicity).
The oscillation circuit 7 includes an inductance coil 8
and a variable capacitor 9 (hereinafter referred to as sensitivity controller 9) which functions as a sensitivity controller of the flaw detector.

The action of the sensitivity controller can be performed in the same way by other elements of the oscillator circuit.

The defect detection means 5 (FIG. 1) includes a blue display detector element 10 and a light display detector element 11, both connected to the tuned amplifier 4. One output of the multivibrator 12 connected to the blue display detector element 10 is connected to a sound indicator 13. The other output of the multivibrator 12 is connected to a DC amplifier 14, the output of which is connected to a needle indicator 15. A light indicator 16 is connected to the light indicator detector element 11. The electromagnetic flaw detector of the present invention operates as follows.

The electromagnetic transducer 2 of the self-excited oscillator 1 is placed on a standard sample with an artificial cut-shaped defect, and the frequency of the self-excited oscillator 1 is adjusted according to the material of the test part. The flaw detector according to the invention is adjusted to maximum sensitivity by turning the knob of the sensitivity controller 9 (FIG. 2) contained in the oscillator circuit 7 of the tuned amplifier 4.

When scanning the inspection part with the electromagnetic transducer 2 (FIG. 1), the Q factor of the oscillation circuit 7 of the self-excited oscillator 1 decreases,
Its natural frequency increases. The changing signal is then sent through the follower 3 to the tuned amplifier 4, and the output signal strength of the tuned amplifier 4 suddenly increases. The signal detected by detector element 10 causes the frequency of multivibrator 12 to change.

The tone of the sound indicator 13 increases sharply. The strength of the signal applied to the input of DC amplifier 14 increases. The needle of indicator 15 suddenly moves. An increase in the tone of the sound signal and a deflection of the indicator 15 indicate a defect in the inspected part.

The signal detected by the detector element 11 is detected by the optical indicator 16
sent to. The angle of the shadow sector of the screen of the light indicator 16 drops abruptly with respect to the initial angle, likewise indicating a defect in the inspected part.

The resonant frequency of the amplifier 4 is thus adjusted by the sensitivity controller 9 according to the material of the test part. The gain of the tuned amplifier 4 is greatly increased and, as a result, the sensitivity of the flaw detector is also increased (at least for a surface defect depth of 0.2 cod, and for a small (both for a length of 0.6111 m)). For a given sensitivity of a flaw detector, component inspection reliability is high, and this feature is extremely essential for inspection of products such as aircraft engine turbine components, including shafts, disks, and blades.

Since only a single electromagnetic transducer is used to inspect parts made of different metals, the operation and maintenance of the flaw detector according to the invention is extremely simple.

[Brief explanation of the drawing]

FIG. 1 shows a block diagram of an electromagnetic flaw detector according to the invention, and FIG. 2 is a schematic diagram of a tuned amplifier incorporated in the electromagnetic flaw detector shown in FIG. 1... Self-excited oscillator, 2... Electromagnetic transducer, 3... Follower, 4... Tuned amplifier,
5... Means for detecting defects in inspected parts, 6...
Amplifier element, 7. Para oscillation circuit, 8. Inductance coil, 9. Flaw detector sensitivity controller, 1
o...Detector element, 11...Detector element, 12
...Multi-vibrator, 13...Sound indicator,
14...Amplifier, 15...Needle indicator, 16...
・Light indicator. Patent applicant representative Patent attorney Fumi Sato (and 1 other person) Zan Uritsutsa Dekabristov 184 Ei Kwarchila 73 0 Inventor Viktor Alekseevitch Nikolaev Soviet Union Kazan・Chistopolskaya UμPinotsa 3 Kwarchila 16 0 Inventor Mikhail Leonidovich Yakusiyev Soviet Union Kazan Ulitsya Frunze 1 Kwarchila 7 0 Inventor Georgy Alekseevytsy Alekseev Soviet Union Kazan Ulitsya Soldatskaya 3 Kwarchila 27 0 Inventor Anatoliy Vladimirovitch Retunov Soviet Union Moscow Uμ Tutua 3 Priadeylnaya 5 Kwarchia 8 ■Applicant Pavel Aleksandrovich Novovitov' Soviet Union Moscow Chernitsynskii・Proezd 4 Kwarchila 23 ■Applicant: Kvgeny Alekseyevich Kniazev, Soviet Union, Moscow Belozerskaya Ulitssa 17 B. Kwarchila 105 ■Applicant: Rinat Shagavalevich Shagabeyev, Soviet Union, Kazan Ulitsa Dekabristov 184 Ei Kwarchila 73 ■Applicant Viktor Alekseevitzy Nikolaev Soviet Union Kazan Chistopolskaya Ulitza 3 Kwarchila 16 0 Applicant Mikhail Leonidovich Yakusiev Soviet Union Kazan Ulitza Frunze 1 Kwarchila 7 0 Applicants Georgiy Alekseevich Alekseev Soviet Union Kazan Uritsa Soldatskaya 3 Kwarchila 27 0 Applicants Anatoly Vladimilovitch Retunov Soviet Union Moscow Uμ Tutua 3 Priadelnaya 5 Kwarchila 8

Claims (1)

[Claims] An electromagnetic flaw detector comprising a self-excited oscillator (1), one inductance coil of which acts as an electromagnetic transducer (2), and further means ( 5) connected in series with said oscillator, said detector being electrically connected to the output of the self-excited oscillator (1) and means for detecting defects in the test component. (5) has a tuned amplifier (4) connected to the input of the tuned amplifier (4), one element of the oscillator circuit (7) in the tuned amplifier (4) acting as a sensitivity controller (9) of the flaw detector. An electromagnetic flaw detector characterized by: