METHOD AND DEVICE FOR CONTROLLING, CHECKING OR OPTIMIZING PRESSURE OF CUSHION PIN CYLINDERS OF PRESS BY DISCHARGING FLUID OR INITIAL PRESSURE

摘要

A cushioning apparatus for applying a blank-holding force to a pressure member to hold a blank on a press, through hydraulic cylinders on a cushion platen biased by a force generating device toward the pressure member, and cushion pins linked with the cylinders and supporting the pressure member, the blank-holding force being based on a biasing force generated by the force generating device, and controllable by a controller through a flow regulator provided in a discharge line for discharging the fluid from the cylinders, such that the controller controls the flow regulator to discharge the fluid from the cylinders during a pressing action on the blank by upper and lower dies, for thereby controlling the cylinder pressure according to a predetermined pattern of change in the pressure in relation to a downward movement of the upper die. The hydraulic cylinders may be classified into two or more groups connected to mutually independent discharge lines. The cylinder pressure may be optimized by disclosed methods and devices.