SU376127A1 - SEEBRING - Google Patents

Description

one

Offered (electrodynamic sensor of ultrasonic waves with an adjustable insertion angle) Designed for non-contact excitation of various TYPES of ultrasonic oscillations, as well as for oblique insertion of shear vibrations into a controlled product and can be used in ultrasonic flaw detection.

A known electrodynamic ultrasonic wave sensor with an adjustable input angle, containing an excitation coil, a generator and a magnet, in the grooves of which three independent windings are stacked, shifted relative to each other and connected to three independent electric generators through delay lines, is cumbersome. a generator for driving the excitation coil.

The purpose of the invention is to simplify the design.

This goal is achieved by combing pole-type lugs at the poles of a magnet, the protrusions of one of which fit into the troughs of the other.

FIG. 1 shows a block diagram and a design of an ultrasonic wave electrodynamic sensor; in fig. 2 a, b, c schematically depicts the principle of the sensor.

An electrodynamic ultrasonic wave sensor with an adjustable insertion angle consists of two pole tips of comb-type 1, mounted on the poles of permanent magnet 2. Due to this, the protrusions of one tip enter the hollows of the other, and an alternating constant magnetic field is created above the surface of the test piece. In the grooves of the 3 pole tips laid three independent windings 4, shifted relative to each other. These windings are connected to three current generators 5 via electric signal delay lines 6.

The proposed sensor works as follows. An alternating electrical voltage of such a frequency is applied to the sensor coils. With such a phase shift, the speed of movement of the eddy current (Fig. 2a), induced in the test surface, would be equal to the speed of the ultrasonic wave. As a result of the interaction of a running eddy current / vortex. (Fig. 2 b) with an alternating magnetic field created by a magnet on the surface of the part, a traveling ultrasonic wave will appear (Fig. 2c). Depending on the speed of the traveling ultrasound wave, a Rayleevsk, Lambowska, or a shear wave with an inclined beam is excited on the surface of the part. The angle of entry is determined by the frequency of the current that feeds the catches, since the frequency of the current determines the speed of movement of the traveling ultrasonic wave.

Subject and item b p. etn e Electrodynamic transducer for ultrasonic waves with an adjustable input angle, containing an excitation coil, a generator and a magnet, in the slots of which three independent windings are laid, shifted relative to each other

The other and connected to three electric generators through delay lines, characterized in that, in order to simplify the design, comb-type pole tips are fixed at the poles of the magnet, the protrusions of one of which enter the hollows of the other.

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