DRIVING DEVICE OF MACHINE PRESS

PURPOSE: To obtain a press drive apparatus capable of adjusting various drawing depths of a press tool at each case by connecting a pressure medium container to a pressure medium chamber through a releasable check valve freely flowing thereto. CONSTITUTION: A pressure point of a ram 2 is formed as a double action cylinder having a differential action piston 1. A telescope piston 6 of a telescope cylinder 5 fixed to the ram 2 is forcedly driven by a stopper 7. A pressure medium chamber 37 is connected to an upper side pressure medium chamber 3 through a releasable check valve 35 freely flowing thereto. A lower side pressure medium chamber 4 is connected to a pressure medium container 27 through a throttle valve 10 capable of cutting off corresponding to relative motion of the piston 1. The pressure medium container 27 is connected to the pressure medium chamber 37 through a releasable check valve 20 freely flowing thereto. By this method, the productivity of the press is increased.