Експериментальні дослідження контактного точкового зварювання деталей сільськогосподарських машин

Abstract

Наведено результати експериментальних досліджень процесу контактного точкового зварювання. Предметом дослідження було вибрано зусилля стиснення електродів під час контактного точкового зварювання деталей сільськогосподарського призначення, або зварне зусилля. На основі побудови та проведення багатофакторних експериментів отримано рівняння регресії зварного зусилля. Емпіричні моделі функціонально описують характер зміни зварного зусилля залежно від чотирьох факторів: відстані між звареними точками; зазору між звареними точками; відстані від кромки листа до звареної точки; товщини деталей, які зварюються.

In the article the results of experimental studies of contact spot welding process of the agricultural machines parts are presented. The subject of experimental studies was selected the compression force of electrodes, which occurs during the implementation of the contact spot welding of sheet parts, or welding efforts in the core of welding area. Basic criteria of physical processes similarity theory during formation of connections of parts with varying thickness by resistance spot welding method have been described. Implementation method of experimental investigations of compression force on electrodes during contact spot welding of the parts has been presented. Deformation of samples was performed on the experimental setup, which was made on the basis of the bursting machines UMM-5. Based on matrix of multifactorial experiments and experimental studies of two side contact spot welding of the parts with different thickness, regression equation for determining the compression force on electrodes has been obtained. Approximating function that describes the behavior of optimization parameters was taken in the form of functional dependence polynomial of the second degree. Empirical models describing the functional nature of the compression effort change of electrodes are based on four factors: the distance between welded points; the gap between the welded points; distance from the edge of the sheet to the welded point; thickness of the welded parts. It was found that with the increase of distance between welded points t in the range 60 140 mm electrodes compression force P1D, which is in the range of change P1D = 0,1...3,3 kN decreases, and there is a significant decline of P1D if the value 80 мм is from 1,5 to 0,1 kN. The dominant factor that most significantly effects on increase of compression effort on electrodes is thickness of the parts s – growth intensity P2D from 0,3 to 3,5 kN is observed, when the value 3 mm.