MECHANISM FOR HIGH PRETENSIONING OF BLANKS WITH THE VIEW OF FINE STAMPING BY MULTIFUNCTION PRESSES

摘要

The invention relates to a mechanism for highly pretensioning the blanks to be subjected to fine stamping by multifunction presses, the said mechanism consisting of a subassembly (A) which is mounted on the press plate and a subassembly (B) which is mounted on the press ram. According to the invention, the mechanism has a subassembly (A) consisting of an upper plate (1), an upper frame (2) and four guide columns (3) embedded, at one end, into the upper frame (2) and, at the other end, into the plate (1), where along said guide columns (3) there moves vertically a pressing plate (4) comprising four guiding bushings (6) and four nuts (8) with worm crowns wherein the eyebolts (9) are screwed, they being articulated with a left lower arm (10) and a right lower arm (11), articulated, in their turn, with the system of left upper arms (15) and the system of right upper arms (14), respectively, which, at the other end are articulated to the right bearing (20) and the left bearing (21), respectively, which, in their turn, are embedded into the fixed upper frame (2), the vertical motion of the pressing plate (4) being given by the subassembly (B) which is mounted on the press ram and comprises a plate (38) on which there are mounted the left pad (34) and the right pad (35) provided with two pitched zones (P1 and P2) pressing on the knuckle joint of the articulation between the left lower arm (10) and the left upper arms (15) and between the right lower arm (11) and the right upper arms (14), respectively, by means of the rollers (18), the optimal adjustment of the blank material pretensioning on the pressing plate (4) being provided by a finely adjusting mechanism which, by means of a worm-worm gear assembly, transmits the motion to the nuts (8) which, by their rotation, move the pressing plate (4) up or down in relation to the lower plate (1).