A method and device for the bending of sheet metal plates of sheet metal blanks into a cylindrical form bodies

摘要

An apparatus for bending a substantially planar, plastically deformable sheet-metal blank or plate into a shell of cylindrical curvature comprises two normally provided spaced apart die bars mounted on a die bed plate and a punch edge provided on a punch member, the punch edge being arranged, upon stepwise advancement of the plate, to press said plate down between the two spaced apart die bars. For the purpose of bending respective end parts of the plate, which is effected by so-called eccentric bending, the apparatus includes at least one additional die bar which is located at a greater distance from the end in question of the plate and at a higher level than that one of the two normally provided die bars located furthest from the end of the plate, and functionally replaces the one normally provided die bar. Preferably the apparatus includes a further die bar located outside each of the two normally provided die bars. The invention also relates to a method for bending a sheet-metal blank or plate into a shell of cylindrical curvature.