SU1295314A1 - Transducer for magnetotelevision flaw detector - Google Patents

Abstract

The invention relates to non-destructive testing methods. The aim of the invention is to improve the reliability of defect detection by using a phase-pulse comparison method with unals. The magnetically sensitive unit 1 converts the signal of a defect into an electrical impulse, which amplifies the amplifier 2 and is fed through the amplitude selector 3 to the video control unit 4. The magnetically sensitive unit 1 is implemented in the form of a matrix of ferrite cores and is located on an elastic base, which allows it to be superimposed on products of various shapes. The scanning unit 6 switches the polled cores simultaneously with the movement of the electron beam on the screen of the video control unit 4, which establishes a one-to-one correspondence between the position of the defect and its display on the screen. The introduction of a triangular bias current driver increases the sensitivity of the device to minor defects. 5 il. (C SL IND CO sd oo 4 ;: FIG

Description

1295314

The invention relates to methods for non-destructive testing of the structure i of ferromagnetic materials and products and can be used in the engineering industry to detect defects in structures and products.

The purpose of the invention is to improve the reliability of defect detection through the use of a phase-pulse method of comparing signals.

FIG. 1 shows a block diagram of the device; in fig. 2 - interaction of the magnetic field with the core; in fig. 3 shows the magnetically sensitive structure of FIG. 4 - signal plots in the interaction with the defect; in fig. 5 shows a scanner design with a triangular pulse former.

The device contains a magnetosensitive unit 1 connected in series, a differential amplifier 2, an amplitude selector 3 and a video control unit 4. The device contains a synchro generator 5 on the screen of the video control unit 4 jiMT and the light field is observed to be connected to a magneto-sensible light (raster).

15

20

6 sweeps by clock pulses delivers the triggered current pulses generated by the shaper, triangular in shape, to a 9-10 horizontal system: and vertical address drives, sequentially selected by one horizontal and one vertical wire. In this case, the ferrite core 8, which is located at the intersection of the corresponding address wires, is re-magnetized (Fig. 4) from one saturated state to the opposite one, and from the magnetization reversal, diametrically located sections (Uch. 1 and Uch. 2) in diametrically located and wound EMF of the same amplitude is induced on these areas of the turns of the output winding 12. These EMFs compensate each other in the absence of a floor defect Nd, since it is diametrically located3

The windings of the Vcod winding 12 are included in the opposite direction. Therefore, there are no signals in the output winding 12 and

the host node 1 and the video monitor unit 4, and the scanner unit 6, V1 is connected between the output of the clock generator 5 and the input of the magnetically sensitive node 1. In FIG. 1 also shows object 7 controls.

The magnetically sensitive unit 1 is made in the form of a matrix (FIG. 3) of ferrite cores 8 with a rectangular hysteresis loop, stitched with a system of 9-10 address wires, a system of magnetization reversal 11, flashing all ferrite cores against the system of 9-10 address wires, and output winding 12 stitching all 8 cores in a diagonal direction

The block and the sweep contains the shift register 13, the current keys 14, the control inputs of which are connected to the outputs of the shift register 13, and the triangular pulse driver, made in the form of a serially connected key 15, the control input of which is connected to the clock input of the shift register 13, and inductance 16, and connected to the current keys 14.

The device works as follows.

Magnetosensitive node 1 is located on object 7 controls. Block

five

on the screen of the video control unit 4 | one can observe the light field of a uniform luminescence (raster).

five

0

6 sweeps in clock pulses are supplied by coinciding in time pulses of current, formed by the shaper, of a triangular form on a system of 9-10 horizontal: and vertical address drives, selected successively by one horizontal and one vertical wire. At the same time, the ferrite core 8, which is located at the intersection of the corresponding address wires, is re-magnetized (Fig. 4) from one saturated state to the opposite state, and from the magnetization reversal, diametrically located sections (Uch. 1 and Uch. 2) in diametrically located and The windings of the output winding 12 wound on these areas are induced by an emf of the same amplitude. These EMFs compensate each other in the absence of a sex defect Nd, since it is diametrically located3

The windings of the Vcod winding 12 are included in the opposite direction. Therefore, there are no signals in the output winding 12 and

0

0

-five

If fi of the control object 7 is a defect and it creates a magnetic field of the defect, the magnetic field of the defect in each core branches out and passes in the section Uch, 1 opposite the field of the current of the survey, and in the section Uch.2 in the same direction as the field of the current survey. This passage of the defect field along the core is provided by the orientation of the matrix in the field of the defect (or magnetizable device). In the plot Uch. The 2 cores of the defect field and the triangular-shaped survey current field are folded. This leads to a displacement of the triangle polling field (Fig. 4). If the remagnetization of the core section 2 of the core in the absence of a defect field occurs at point 1, then in the field of the defect renegotiation occurs earlier at point 1 due to the displacement of the triangular polling field by the field of the defect. In the case of magnetization reversal at the moment of time determined by point 1, an impulse of EMF arises, which is

55

Phase impulse emf arises at time 1 in the absence of a defect. On the contrary, the defect field is subtracted from the interrogation current field in the core section U.1 of the core and shifts the triangular interrogation field in the opposite direction. Magnetization reversal

3 1,

plot Uch, 1 occurs later p moment 2, when in the absence of a defect the magnetization reversal occurs at time 2. Therefore, in the field of a defect in the single turn winding of section Uch.1, an EMF pulse arises that is lagging in phase. Since the single-turn windings of the sections are included in the opposite direction, these EMFs are directed in the opposite direction, but can no longer compensate each other, since they are separated in phase by the Field of the defect. In the output winding 12, a signal appears, the amplitude of which is proportional to the strength of the field of the defect in a certain range. The signal from the output winding 12 is supplied to the input of the differential amplifier 2 for amplification, then to the amplitude selector 3 and enters the video control unit 4.

Due to the synchronous operation of the video monitoring unit 4 and the scanning unit 6, a spot is formed on the screen, the position of which corresponds to the defect on the control object 7. The brightness of the light spot is controlled by an amplitude selector.

Claims (1)

Invention Formula Converter to magnetotelevical flaw detector containing mag ten 953144 a thread-sensitive node made in the form of a matrix of ferrite cores with a rectangular hysteresis loop, mounted on a flexible elastic base and stitched with a system of address wires, a magnetization reversal bus stitching all ferrite cores to counter addressed wires, and an output winding stitching all ferrite cores in diagon direction connected in series with a differential amplifier connected to the output winding, amplitude selector and video monitoring unit, clock generator, cat outputs The op is connected to a video monitoring unit and a magnetically sensitive node, and a scanner connected between the sync generator and address wires of the magnetically sensitive node, characterized in that, in order to increase the reliability of defect detection, the scanner is equipped with a triangular shaped pulse shaper, and the output winding the ferrite core is made in the form of two diametrically located coils, the planes of which are perpendicular to the control surface oppositely interconnected. 15 20 five 0 71 . 9 ten FIG. g fig.Z Totfm ecu Phage. / 3 FIG. five Compiled by Yu. Glazkov Editor E. Papp Tehred I. Popovich Order 612/51 Circulation 777. Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d, Proizvodstvenno-p ygrafychy enterprise, Uzhgorod, st. Project, 4 Proofreader A.T. sko