Method for automatic adjustment of the travel of a stretching rod of a device for forming hollow bodies

Method for adjusting the travel of a stretching sliding rod (24) that belongs to a device (14) for forming hollow bodies (18) made of thermoplastic material by stretch blow molding, with the stretching rod (24) being controlled cyclically in terms of sliding from a rest position to an adjustable stretching end position so as to stretch the malleable wall of a hollow body (18), before returning to the rest position to begin a subsequent stretching cycle of another hollow body (18), with the method comprising a control step (E1) that consists in detecting whether an axial force that opposes the sliding of the stretching rod (24) at the end of travel is above a determined upper boundary;

• wherein the stretching end position of a subsequent stretching cycle is adjusted automatically by being subjected to the axial force that is detected during the control step (E1).