METHOD OF STABILISING HEAT RELEASE IN CONTACT POINT WELDING Russian patent published in 2011 - IPC B23K11/24 

FIELD: process engineering.

SUBSTANCE: invention is intended for automatic control over contact welding machines. Prior to welding, supply circuit voltage U_c, factor of transformation at given stage K_t, welding machine inductive impedance X_2k and angle φ_k of current lag behind voltage in full-phase switching-on in short-circuit conditions are determined. In every cycle of welding current, power factor cosφ, heat release q at "electrode-electrode" section are determined to select thyristor opening angle α' in next cycle. With due allowance of obtained data, heat release q for current period is determined by preset formula. Required heat release q' in next period is set by correction of thyristor opening angle α' proceeding from condition of equality between total heat release during preset number of welding current periods n_h and preset heat release Q allowing for past current periods j.

EFFECT: higher contact point welding quality.

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