GB1229539A - - Google Patents

Abstract

1,229,539. Forging crank-shafts. COMPAGNIE DES ATELIERS ET FORGES DE LA LOIRE (ST. CHAMOND FIRMINY-ST. ETIENNE-JACOB-HOLTZER). 14 July, 1969 [19 July, 1968; 24 Feb., 1969], No. 35354/69. Heading B3H. A crank-shaft forging apparatus comprises a pair of cradles 3, 3<SP>1</SP> adapted to move horizontally on a slide by the interaction of inclined slideways 7 to upset the blank 8 and upper and lower crank-pin dies 10, 11 to offset the upset portion, the upper die being mounted on a piston 13a in an hydraulic cylinder 13 which is connected to a reservoir through a discharge valve to allow initial simultaneous upsetting and offsetting and a final upsetting in which the crank-shaft webs are formed. The valve (not shown) is preset as a function of the blank size to cause the downward movement of the upper die 10 to stop after the offsetting. Alternatively the cylinder may have a pair of discharge valves to permit initial upsetting, intermediate simultaneous upsetting and offsetting and final upsetting. The cradles 3, 3<SP>1</SP> carry blank holding blocks 14-17 with flat faces adjacent the dies 10, 11 whose faces are recessed, 20, 22, to define limits for the crank-web size. Alternatively, Figs. 5, 7 and 8 (not shown), the faces of the blocks and/or the die may be recessed. The lower crank-pin die 11 is also mounted on a piston 12a of an hydraulic cylinder 12 which holds the die in position until a pre-set pressure. Auxiliary hydraulic actuators 18, 18<SP>1</SP> also serve to move the cradles 3, 3<SP>1</SP>. The lower assembly of the apparatus can be removed from the press bed 1 for loading with a blank. In an alternative embodiment, Fig. 10, the cradles 43, 43<SP>1</SP> are slidable on slideways 44, 44<SP>1</SP> and carry lower dies 54, 56 which co-operate with upper dies 55, 57 carried by die blocks 63, 63<SP>1</SP>. The blocks 63, 63<SP>1</SP> are suspended from an upper crosshead 45 by pairs of hydraulic rams 64, 64<SP>1</SP>. The rams move the blocks along slideways 47, 471. In operation, the cradles. 43, 43<SP>1</SP> and blocks 63, 63<SP>1</SP> are separated against stops. The upper crosshead is lowered until the upper and lower dies 54-57 interengage and then the upsetting stroke effected by movement of the upper blocks along the slideways 47, 47<SP>1</SP>. The offsetting of the throw is effected using upper and lower dies 50, 51 in the manner of the first embodiment. (For Figures see next page)