SU945773A1 - Method of non-destructive control of spot welded joint quality - Google Patents

Description

(54) METHOD OF NON-DESTRUCTIVE QUALITY CONTROL OF POINT WELDED CONNECTIONS

one

The invention relates to non-destructive contraction and can be used to control the quality of spot welded joints.

A known method for non-destructive quality control of spot welded joints is a scientific research institute, which implies that the eddy currents of high and low frequencies excite the quality of point welded joints 1 using two electromagnetically controlled transducers.

The disadvantage of this method is the lack of hopefulness due to the effect of the variation of the electrical conductivity of the materials being welded on the control results.

The closest to the technical essence of the invention is the method of non-destructive quality of spot welded joints, consisting in that the core of the weld point is affected by an electromagnet converter with variable and constant electromagnetic fields and the change in the parameters of the electromagnetic converter 2J is determined.

However, the known method also does not have the necessary reliability of control, which is associated with the influence of the gap variation on the control results, as well as with the exception of the influence of the informative value of the magnetic core permeability

iO on the value of the recorded signal.

The purpose of the invention is to increase the reliability of the control.

Claims (1)

This del is achieved by the fact that on | A constant magnetic field is changed over a linear value, starting from zero, an inductive output of its winding is chosen as an informative parameter of the electromagnetic transducer, the derivative magnetic field is measured, the intensity value is measured, corresponding to maximum, and by co (I hMniocTii of the obtained values, it will limit the quality of the monitored point to “shocked s-joint”. The method is implemented as follows. On a controlled basis The solenoid transducer has an electric transducer installed, having windings connected to AC sources and a Yushupnoshe circuit for measuring H5 current strength, respectively. If the linear magnetic flux increases from the zero linearity, an increase in the magnetic permeability L in the zone will be displayed. inverter inductance Pr with a maximum value of c (the dependence dt y / dN-f (H where H is the strength of the constant linear variation of degos waves is maximized m. With the help of known means, the magnitude of the winding connected to the AC source is measured, and the maximum of the measured value and the value of the maximum magnetic field constant voltage are recorded. According to the consistency of the obtained values, the court is t-as a spot welded joint. between the end of the electromagnetic converter and the thermal conductivity of the object being monitored. This provides an increase in the reliability of the control. welded joints, in that the weld point is acted upon by an electromagnet converter with alternating and constant magnetic fields and the change in the parameters of the electromagnetizer converter is determined, in order to reliably control , the intensity of the constant MapField field 1 from the right to earth law, starting from zero, is taken as the informative parameter of the electromagnet Nyt converter that produces the inductance of its winding about the strength of a constant magnetic field, we derive the maximum of the derivative, the magnitude of the intensity, corresponding to its maximum, is measured, and the quality of the monitored spot welded joint is determined from a set of values. Sources of information received in the review during the examination 1.Avtskoe certificate of the USSR No. 336587, kp, GO1N 27/86, 1970. 2, USSR Author's Certificate for Nb 2769151, cl. CiOl N 27/9O, 1979 (prototype).