SU979982A1 - Strapped converter for eddy-current flaw detector - Google Patents

Description

(54) COVER CONVERTER TO VORTEX CURRENT DEFECTOR

one

The invention contributes to non-destructive quality control of the material of the products by an electromagnetic method and can be used as part of defectoscopes to detect surface defects in all areas of engineering.

Known invoice transducer to the eddy current flaw detector, containing two indicator coils, included counter and inductor coil, covering indica.tornye 1

The disadvantage of the converter is that, at its output, there is always an unbalance emf associated with the position of the indicator coils relative to the inductor axis, each other, or the difference in the values of the inductances of the coils, which ultimately reduces the sensitivity and resolution of the converter.

The closest in technical essence to the present invention is an invoice transducer to an eddy current flaw detector, comprising indicator coils, an inductor coil. encircling the indicator, and a compensator, made in the form of an electrically conductive sleeve with a slot and mounted for rotation around its axis and. reciprocally moving along it, the compensator is positioned by inductor —And indicator coils, indicator coils, symmetrically arranged, consist of two pairs of inductance measuring coils interconnected in pairs and in pairs with a consistent connection of pairs (2).

to

However, the transducer does not provide sufficient reliability for the counterspace due to the fact that an electrically conductive sleeve (compensator) located between the inductor and indicator coils protects (shunt) the electromagnetic field created by the inductor coil, therefore the density of the vortex tube induced on the product is significantly reduced . In addition, the presence of four measuring coils reduces the efficiency of compensation of induced EMF using a compensator.

Claims (2)

The aim of the invention is to increase the reliability of the control units. This object is achieved in that the trim converter to eddy current defekggosko T} soderzhshdem ivdikatornye coil W duktor first coil enclosing I1-schikatoriye, and a compensator arranged in the form of electron oopropod 1tsey bushing t ggrorezyu n ustaaovleniy chance povorotavokrug its axis compensator covers inductor coil. FIG. 1 shows the eddy current transducer, general view; in fig. 2 - ay teachings on phpg. 1. The powering device consists of two inclusive indicator coils 1.2 inductor coil 3, covering indicator, compensator 4, made in the form of an electrically conductive sleeve with slot 5, wearing a converter case b and covering the transducer coil 2. Case transformer b is made from / electric material (on) trimer, textolite). Compensator 4 has the ability to rotate about its longitudinal axis 7, i.e., slot 5 of the electrically conductive sleeve can move relative to the axis of symmetry of the converter. Transducer compensation is achieved as follows. Using the inductor satush 3, a high-frequency electromagnetic field is created. In indicator coils 1, 2, are located symmetrically relative to the longitudinal axis 7 of the converter; induced emf caused by this zero. In citny symmetrical floor, the resulting emf of identical coils 1, 2, inclusive, must be equal to; However, due to the technological variation associated with the accuracy of manufacturing, winding and placing the indicator tubes relative to the axis of symmetry, the EMF is unbalanced to D UpgT, at the output of the converter. In the case of a gap with respect to its axis of the compensator 4, in the form of an electrically conductive sleeve with a slot 5, in the region of which the electromagnetic field is non-uniform, an additional unbalance EMF appears in the indicator coils 1.2. The induced emf will be added or subtracted from the emf imbalance D Upcj3 caused by the technological variation in the manufacture of the converter. Rotating the sensor 4, find the position of the slot 5 relative to the indicator catches, at which the emf of the imbalance of the technological scatter becomes minimal. The selected position of the compensator 4 fyusiruyut. The width of the slot 5 of the compensator 4 should not be more than half the distance between the centers of the indicator coils. Above 1 slot, the gap reduces the efficiency of compensation due to the simultaneous effect of the local heterogeneity of the current line 5 on the indicator coils 1 and 2. In addition, the compensator is additionally a concentrator of the electromagnetic field. The use of the invention allows to significantly increase the reliability of control of eddy-current flaw detectors of the surface of products made of ferromagnetic and nonmagnetic steels and alloys. The use of a converter with a compensator provides detection of defects with a depth of 0.05–0.08 mm on the surface of calibrated rods with a signal: interference ratio 5 or more times. Claims Invoice transducer to an eddy current flaw detector, comprising indicator katuschki, inductor coil covering and switch, and a compensator, made in the form of an electrically conductive sleeve with a slot and installed with the possibility of rotation around its axis, characterized in that, in order to increase the reliability of control, the compensator covers inductor coil. Sources of information taken into account in the examination 1.Dorofeev A.L. and Nazamanov Yu.G. Electromagnetic flaw detection. M, Mechanical Engineering, 1980, p. 165-167 fig. 81, 83. 2. USSR author's certificate number 616574, cl. G 01 N 27/90, 1977 (prototype). 2