Process and machine for parting the cap of connecting rods, particularly connecting rods for internal-combustion engines

摘要

According to the invention, parting of the cap (12) of the connecting rod (11) is achieved by engaging the eye of the big end of the connecting rod with two semicylindrical fixtures, respectively a fixed fixture (15) and a movable fixture (17), which are actuated by a hydraulic actuator (24) which is interposed between them and is adapted to expand the fixtures in a diametrical direction against the inner surface of the eye of the big end of the connecting rod, subjecting the piston (25) of the actuator (24) to the action of a hydraulic fluid fed into the respective actuation cylinder (26) at an optional pre-loading pressure that is in any case lower than the pressure required to reach the yield point of the material of the connecting rod, and producing an instantaneous peak in the pressure of the fluid fed to the hydraulic actuator (24) by means of an auxiliary piston (35) that is subjected to the momentary action of a striking mass (42).