Assembly for manufacturing a metal part and use of such an assembly

A manufacturing assembly for manufacturing a metal part, the manufacturing assembly comprising:

• a chassis provided with a station that receives the metal part;
• a flattening module that includes a trolley, and the flattening module including at least one pressing roller connected to the trolley, the metal part having two edges hemmed to one another, the two edges hemmed to one another defining a hemming line having a free surface;
• a longitudinal drive arranged to move the flattening module relative to the chassis along the hemming line when the metal part is at the station;
• and
• the flattening module including at least one pressing actuator that is arranged to move the at least one pressing roller in a determined pressing direction relative to the trolley and to place the at least one pressing roller to bear against the free surface such that the at least one pressing roller exerts pressure on the free surface in said determined pressing direction, the pressure increasing auto-adaptively with an altitude of the free surface that increases in a direction opposite the determined pressing direction;
• wherein the at least one pressing actuator or each pressing actuator is a resilient compression member having a compression axis that extends in a direction common with the determined pressing direction;
• wherein the resilient compression member or each resilient compression member includes:
• a body having a bottom, and
• a piston movable inside the body in the determined pressing direction relative to the bottom;
• and
• wherein a sealed chamber including a pressurized gas is delimited between the bottom and the piston;
• wherein the trolley, for the at least one pressing actuator or each pressing actuator includes:
• an inner cavity in which the at least one pressing actuator is housed, or
• a plurality of inner cavities where each pressing actuator is housed in one inner cavity of the plurality of cavities, or
• an inner cavity in which each pressing actuator is housed, and
• a rotational guide bearing for each piston;
• wherein a lower bottom delimits the inner cavity in the determined pressing direction and limits travel of the at least one pressing roller in the determined pressing direction, or wherein a respective lower bottom delimits each inner cavity of the plurality of cavities in the determined pressing direction and limits travel of each pressing roller in the determined pressing direction;
• and
• wherein the two edges hemmed to one another have a distal end part that is folded against a body of the metal part along the hemming line, and wherein the hemming line includes at least a first section having a first thickness and a second section having a second thickness greater than the first thickness, and wherein the flattening module is configured to flatten the first and second sections by:
• prior to the at least one pressing roller or each pressing roller being in contact with the hemming line, the at least one pressing actuator or each pressing actuator is configured to apply a predetermined pressure to the at least one pressing roller or each pressing roller such that the rotational guide bearing or each rotational guide bearing abuts against the lower bottom of the inner cavity or each inner cavity to determine an initial altitude of the at least one pressing roller or each pressing roller in the determined pressing direction taken relative to a reference surface, and
• when the at least one pressing roller or each pressing roller bears against a first section of the free surface, located at a first altitude greater than the initial altitude, the at least one pressing roller or each pressing roller is moved relative to the trolley in the direction opposite the determined pressing direction such that pressure exerted by the at least one pressing actuator or each pressing actuator on the at least one pressing roller or each pressing roller auto-adaptively increases to a first pressure, greater than the predetermined pressure, as a result of gas located in the sealed chamber or each sealed chamber being compressed due to the movement of the piston or each piston.