SU1555079A1 - Apparatus for automatic following of welds - Google Patents

Abstract

The invention relates to the automation of non-destructive testing of welded joints and can be used to automatically guide a non-destructive testing sensor along the axis of reinforcement of a welded joint. The purpose of the invention is to enhance the functionality by eliminating the influence of the product and seam parameters on the tracking process. The device contains an electromagnetic sensor with a supply coil and two according to the included main measuring coils (IR), a follower drive and its control unit, an adder, two converters and a subtractor unit. The device is equipped with a pair according to the included additional IR, the third and fourth converters and the subtraction unit connected in series with them. A second information channel is formed in the device, which, in combination with the first, provides a signal from the output of the adder to the control unit of the follower drive, independent of the difference in the gaps between the IR and the product. 2 Il.

Description

The invention relates to the automation of non-destructive testing of welded joints and can be used to automatically guide a non-destructive testing sensor along the axis of reinforcement of a welded joint.

The purpose of the invention is to expand the functionality of the device.

FIG. 1 shows a functional diagram of the device; in fig. 2 - sensor, embodiment.

The device contains a generator 1, an electromagnetic sensor 2 with a power coil 3 and two according to the included main coils 4 and 5, the follower drive 6 and its control unit 7 with an adder 8, the channel of amplitude signal processing in the form of two drivers 9 and 10 ,. the input of each of which is connected to the ends of the main coils 4 and 5, respectively, and the subtraction unit 1, the inputs of which are connected to the outputs of the drivers 9 and 10, and the output to one of the inputs of the adder 8.

In addition, the device is equipped with additional katuki 12, 13 and connected to them with the second channel amplitude signal processing in the form of two drivers 14, 15 and

ate ate ate about

WITH

subtraction unit 16, the output of which is connected to the second input of the adder 8. The subtractors 8 and 11 and 16 and the adder 8 are operational amplifiers.

The device works as follows.

When the power is turned on, generator 1 produces a sinusoidal voltage applied to the supply coil 3 of sensor 2. The magnetic field of the supply coil 3 excites eddy currents in the product and the reinforcement of the seam, the magnetic fields of which induce EMF in the main coils 4, 5 and additional coils 12 and 13. The signals detected by the imaging units 9, 10, 14, and 15 are fed to the inputs of blocks 11 and 16 of the subtraction, each of which is adjusted so that, in the initial operating state, their outputs have zero voltages. As a result, at the output of the adder 8 and at the outputs of the blocks 1 1 and 16 of the subtraction, the voltage is zero.

When sensor 2 is leaving in any direction from the axis of the seam, as well as in case of misalignment or the difference in thickness of the welded elements in the main and additional coils 4, 5, 12 and 13, EMF is induced, the value of which corresponds to

1 A, X + R, Y + C ,; Uu + E2Y + sa,

(About (2)

where U ,, P2 - EMF in the main and additional coils, respectively; 40

K1,2.

- coefficients determined by the size and shape of the main and additional coils, so 45

A, t-kA2, B, 1 kB, C t kC2,

where k is a constant;

X is the magnitude of the shift of the axis of symmetry of the sensor relative to the axis of the seam;

Y is the amount of change in the gap between the sensor and the product from different sides of the seam.

The shape and size of the coils are selected in such a way as to achieve the implementation of the relations () and (2) in

0 5

Q

five

0

five

0

five

the entire range of real X and Y values.

Then, choosing the gains of the blocks 11 and 16 of the subtraction, provide a linear operation when summing the output signals

U with VGTs -, - AtB ") X +

+ (B20, -).

As a result, the signal U, coming from the output of the adder 8 to the servo driven control unit 7, does not depend on the difference in the gaps between the coils of the sensor and the product. As a result, a total signal arrives at the input of the control unit following the drive, the amplitude of which is proportional to the amount of sensor drift from the weld axis, and the polarity corresponds to the direction of care.

Since the parameters A ;, B and C of relations (1) and (2) are determined only by the characteristics of the coils and are not dependent on each other, the functionality of the device is expanded.

Claims (1)

Thus, the proposed device for automatic tracking of the weld seam allows to expand the functionality by eliminating the need for multiple adjustment of the system depending on the parameters of the product. Invention Formula A device for automatic tracking of a weld, comprising a generator connected to a supply coil of an electromagnetic sensor, including two measuring coils connected to the inputs of two drivers, the outputs of which are connected to the inputs of the subtractor, an adder, one of the inputs connected with the output of the subtraction unit, and the output through the control unit with the input of the follower drive, characterized in that, in order to expand its functionality, it is additionally equipped with a third and fourth the shaper and the second subtractor, the electromagnetic sensor is equipped with two additional coils connected in accordance with the included, connected through the third and fourth shapers with two inputs of the second subtractor, the output of which is connected to the second input of the adder. FIE 1, -U2 Phage. 2