| 摘要 |
1537156 Forging crankshafts INSTYTUT OBROBKI PLASTYCZNEJ 4 March 1976 [15 March 1975] 08602/76 Heading B3H A method of making a crank throw which includes a pair of opposed arms and a pin interconnecting the ends of the arms, comprises forming a blank having a pair of end blocks and a neck interconnecting the end blocks, the neck having end portions diverging towards the end blocks, and displacing the neck laterally of its axis while simultaneously pressing together the end blocks whereby material from the neck forms the pin and material from the blocks forms the arms. The blank is made from a starting piece 14 in the form of a cylinder with an annular groove in its middle and it is placed in a shaping device having shaped segments 11 which locate in the groove. A easing 12 is lowered over the segments to force them radially inwardly and the casing is secured by pivoted hooks 13 engaging a rim portion of a ring 10. When the hooks are engaged, sleeves 15, 16 are removed and the blank is formed in a pressing operation, Fig. 18 (not shown). The blank is then placed in forging dies 6, mounted in holders 22, and it is secured in the dies by wedge shaped inserts 23. Blocks 28 are placed on the inserts 23 and a press ram 27 is actuated through a part of its stroke. The blocks 28 are removed before completion of the ram's stroke and as the ram descends, a punch 8 bears on the neck of the blank to offset the pin laterally, while wedge shafts 26 drive the die holders 22 towards each other to shape the crank arms. |
