Abstract: The object of the invention is a process for forming sectors of the air intake lip of an aircraft nacelle, of U-shaped cross-section, characterized in that it comprises producing, from a cylindrical billet (11) of a suitable material, by hot die pressing, a tubular profile (12) of U-shaped cross-section whose ends are interconnected, a portion of the section formed by the U having a development less by several percent than the development of the smallest cross-section of the lip sector to be obtained, in giving to the profile (12) at the outlet of the die (15) a curvature whose radius is substantially equal to the mean radius of said sector, then in forming and calibrating the profile (12) to the final shapes of the sector by hydraulic expansion in a matrix whose interior corresponds to the external volume of said sector increased by the resilient return of the material to be expanded, and finally, cutting off the tubular product thus formed to separate the portion of U-shaped cross-section constituting said

Abstract: The object of the invention is a process for forming sectors of the air intake lip of an aircraft nacelle, of U-shaped cross-section, characterized in that it comprises producing, from a cylindrical billet (11) of a suitable material, by hot die pressing, a tubular profile (12) of U-shaped cross-section whose ends are interconnected, a portion of the section formed by the U having a development less by several percent than the development of the smallest cross-section of the lip sector to be obtained, in giving to the profile (12) at the outlet of the die (15) a curvature whose radius is substantially equal to the mean radius of said sector, then in forming and calibrating the profile (12) to the final shapes of the sector by hydraulic expansion in a matrix whose interior corresponds to the external volume of said sector; increased by the resilient return of the material to be expanded, and finally, cutting off the tubular product thus formed to separate the portion of U-shaped cross-section constituting said

Abstract: A process for hydroforming sheet metal, in which a blank (1) is secured with the help of a blank holder (2′, 2″, 2′″) on a matrix (4′) provided with a cavity (3′) for stamping the blank (1) with the help of a die (5′, 5″, 5′″) entering the matrix, characterized in that during the stamping phase, the play between the die (5′, 5″, 5′″) and the blank holder (2′, 2″, 2′″) is confined within a range of values preventing, between the die and matrix, the formation of a fold, as a function of one and/or the other of the following parameters: pressure of fluid in the cavity (3′) of the matrix (4′), and position of the die (5′, 5″, 5′″) relative to the matrix.

Abstract: A process for hydroforming sheet metal, in which a blank (1) is secured with the help of a blank holder (2′, 2″, 2′″) on a matrix (4′) provided with a cavity (3′) for stamping the blank (1) with the help of a die (5′, 5″, 5′″) entering the matrix, characterized in that during the stamping phase, the play between the die (5′, 5″, 5′″) and the blank holder (2′, 2″, 2′″) is confined within a range of values preventing, between the die and matrix, the formation of a fold, as a function of one and/or the other of the following parameters: pressure of fluid in the cavity (3′) of the matrix (4′), and position of the die (5′, 5″, 5′″) relative to the matrix.