RU1837221C - Method of non-destructive testing - Google Patents

Abstract

The invention relates to non-destructive testing of objects and can be used for inspection of turbine blades. This flaw detector is carried out by the signals of magnetic heads - recording and reproducing on a magnetic information carrier located on the shaft of the turbine. The signal is transmitted to the recording head from an induction sensor interacting with turbine blades. 1 ill.

Description

E The invention relates to non-destructive means of testing objects and can be used to control blades of turbines.

i There is a known method of defectoscopy of turbine blades, which consists in the fact that in the zone (the expansion of these blades, a constant magnetic field is excited and its changes are fixed, which are used to determine the quality of the rotating blades).

However, the performance of the control In a known manner is insufficient.

 To increase productivity, the control according to the proposed method, the fixation is carried out according to the signals of two magg. thread heads mutually offset by an angle multiple of the number of turbine blades, and for TJ3M these signals recorded on a magnetic storage medium are erased.

i The drawing shows a block diagram of a flaw detector for implementing the method.

The flaw detector contains a permanent magnet 1, covering its signal winding 2, erasing 3. recording 4 and reproducing 5 magnetic heads interacting with a magnetic information carrier located on the turbine shaft 7 with blades 8, a signal comparison circuit 9 and a recording device 10.

The essence of the method is as follows.

When the blades 8 rotate in the field of magnet 1, the signals from the winding 2 correspond to the eddy current interaction of these blades with the indicated field. These signals are recorded by recording 4 and reproducing 5 heads by means of a magnetic information carrier 6. From the reproducing head 5, the signal arrives at one input of the signal comparison circuit 9, and another input of which the signal comes from the winding 2. At a zero level of signals at the output of the circuit 9 there are practically no defects in the blades. Naked

WITH

with

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Flanges 4 and 5 are offset by an angle multiple of the number of blades. The signals are periodically erased by the head 3.

Claims (1)

SUMMARY OF THE INVENTION Mg 236583, characterized in that, for the purpose of To increase the productivity of the control, the signals are fixed by two magnetic heads mutually offset by an angle multiple of the number of turbine blades, and then these signals are erased. x X /