Process and appliance for checking the quality of formings executed by a machine for forming tube ends

Process for checking the quality of formings executed by a machine for forming tube ends, comprising means (1) for holding a tube which are suitable for positioning it so that it extends on a longitudinal axis (x), called the forming axis, at least one tool (9a) for forming an end of the said tube, and means (10-24) of translationally displacing each tool (9a) which are capable of displacing it on the axis (x), between an advanced forming position suitable for enabling the end of the tube to be formed and a retracted position suitable for allowing the unloading of the formed tube and the loading of a new tube, the said process being characterized in that the forming machine is equipped with a force transducer (33) which is capable of measuring the reactive axial force exerted by the tube on the tool (9a) in a forming pass and, for each forming:

• in a preliminary learning phase, the maximum reactive axial force exerted by the tube on the tool (9a) is measured, the quality of the executed forming is verified in conventional manner and the value of the maximum reactive axial force obtained in a forming of a quality meeting the required conditions is recorded,
• then, in each forming pass, the maximum reactive axial force exerted by the tube on the tool (9a) is measured, the value of the said maximum axial force is compared with the recorded reference value and the forming is validated if the measured maximum axial force corresponds to the reference force with a predetermined tolerance.