Twisting method and installation with tension control for the production of reinforcing cords for tires

An installation for manufacturing a wire element by interlacing at least one first strand and one second strand distinct from the first strand, said installation comprising:

• an infeed device responsible for routing the first strand and the second strand, respectively, to an assembly point, at which the first strand and the second strand meet;
• an interlacing device responsible for interlacing the first strand and the second strand with each other, at the assembly point, so as to form a wire element from said at least first and second strands,
• wherein said installation comprises a selector that allows the installation to operate in a “tension control mode” or a “speed control mode;”
• a tension control unit, arranged to control the strand tension in a closed loop according to the tension control mode, said tension control unit to this end comprising:
• a tension setpoint setting component that allows a tension setpoint, called “assembly tension setpoint”, to be set that represents a longitudinal tension state intended to be obtained in the first strand when said first strand reaches the assembly point;
• a tension monitoring component that allows the tension, called “actual assembly tension”, that is exerted inside said first strand to be measured at a first tension measurement point that is located along said first strand and upstream of the assembly point relative to the routing direction of said first strand;
• a tension feedback component that is used to assess an error, called “tension error”, that corresponds to the difference between the assembly tension setpoint and the actual assembly tension of the first strand;
• and
• a tension regulating component, which is dependent on the tension feedback component and which can act on the first strand upstream of the assembly point, so as to automatically converge, inside said first strand, the actual assembly tension towards the assembly tension setpoint;
• and
• a forward speed control unit arranged to control the forward speed of the first strand in a closed loop according to the speed control mode, said forward speed control unit to this end comprising:
• a speed setpoint setting component that allows a setpoint, called “forward speed setpoint”, to be set that corresponds to a forward speed value intended to be imparted to the first strand upstream of the assembly point;
• a speed monitoring component that allows measurement, at a forward speed measurement point that is located along said first strand and upstream of the assembly point, of a speed value, called “actual forward speed”, that represents the actual forward speed of the first strand at the considered measurement point
• a speed feedback component that allows an error, called “speed error”, to be assessed that corresponds to the difference between the forward speed setpoint and the actual forward speed of the first strand;
• and
• a speed regulating component, which is dependent on the speed feedback component and which can act on the first strand upstream of the assembly point, so as to automatically converge the actual forward speed of the first strand towards the forward speed setpoint.