HEAT RELEASE AT CONTACT SPOT WELDING AUTOMATIC MEASURING AND CONTROLLING METHOD Russian patent published in 2007 - IPC B23K11/24 

FIELD: contact welding processes and equipment, namely automatic control of welding machines.

SUBSTANCE: method comprises steps of determining power coefficient cosφ in each period of welding current and value of heat release in zone electrode-electrode. Value of heat release is calculated according to expression q_i = (I₂)² x r _el-el x 0.02, where r_el-el - resistance of zone electrode-electrode; I₂ -acting current value in secondary circuit. If calculated value differs from preset one, decision for performing correction of thyristor ignition angle in next period of welding current is assumed. Angle of thyristor ignition is determined according to given formula α_i+1=α_i·(√q/q_i) +(a₀/a₁)·(√q/q_i-1) where q - preset heat input for period; a_{1 ,} a₀ - coefficients determined empirically on base of power coefficient; α_i - thyristor ignition angle in current period.

EFFECT: improved quality of spot-welded joint having predetermined geometry size regardless of state of electrode and welded part surface in the result of stable heat release in interval electrode-electrode.

2 cl, 3 dwg, 1 ex