GB1462665A - Cold-forming metal articles - Google Patents

Abstract

1462665 Forging GLAENZER SPICER 11 April 1974 [17 April 1973] 16181/74 Heading B3H Apparatus for cold forming metal parts comprises a multi-part die 28 which forms a cavity 90, Fig. 12, when closed provided with radial channels 91 and a set of punches 29, 30 which extend into the die, the punches and die parts being carried by a press piston 26 and table 27. The die parts 28 are mounted on blocks 32 slidable in slots on inclined blocks 35 held between plates 37, 38 urged together by tie bolts 40. The blocks 32 are connected by a toggle linkage 46, 48 to a sleeve 55 slidable on the piston column extension 56. The link 46 acts as a pawl and has a surface 46a adapted to engage under a bearing surface 59 on an abutment member 60. A spring 69 acts between the piston extension shoulder 70 and a shoulder 71 on the sleeve 55. The upper punch 29 is rigidly mounted to the piston 26 and the lower punch 30 is fixed by a ring 81 to a column 75 on the press table 27. The plate member 37 is slidable on the column 75 and urged upwards by three compression springs 77. In operation a workpiece is positioned on the lower punch 30 with the die parts open. The lower punch may be slightly magnetized to retain the workpiece. The piston is moved downwards causing the blocks 32 to slide along the inclined slots. The toggle linkage 46, 48 moves outwards and the pawl engages under the block 60 to cause a prestressing force radially of the die parts to hold them together. The speed of the upper punch 29 is arranged to be one half the speed of the multi-part die. The apparatus is used to rough forge workpieces with radial projections for later finishing. The finishing apparatus, Fig. 18, comprises a pair of dies 105, 106, a vertical punch 107, a first group of three horizontal radially acting punches 108 and a second group of three horizontal radially acting punches 109. The opposed die surfaces have radial half cylindrical passages 114, 117, Fig. 19, for the punches. The punches 108, 109 are mounted at their rear on rectangular plate blocks 210 slidable in a slot in a respective oblique block 212 which is moved downwards by abutment. The lower die 106, Fig. 15, is mounted on a slidable shaft 110 leading to a sleeve 166 controlled by a toggle linkage 187, 189 with a cam follower roller 194 engaging a cam 195 on the press frame. In operation a rough forged workpiece is positioned on the lower die 106 and the press piston 103 lowered to bring the dies 105, 106 together. The dies 105, 106 are lowered together with the punches 108, 109. The punches 108, 109 form bores (13), (19), Fig. 7 (not shown), in the finished articles. The central punch 107 forms a bore (14). The final workpiece may have three or four radial arms at various axial positions of its central hub. The starting billet may be hollow and filled with elastomeric material or liquid during forging.