Adjustment manner and device null of balanced pressure cushion

摘要

PURPOSE: To prevent the quality of a press-formed article from being impaired through changes in the inflow of press materials, which is caused by the variance in the descending stroke of a hold down die until a proper hold down load is obtained, on account of the difference by each press in the piston thrust dimension of a hydraulic cylinder for pressure equalization. ;CONSTITUTION: The supply and discharge of a hydraulic oil is controlled by a pump 34 and a stop valve 36 so that the piston thrust dimension of a hydraulic cylinder 32, which evenly distributes a wrinkle holding load by being put in a neutral state at the time of press forming, coincides with the dimension preliminarily set in accordance with press dies 12, 18, 30 so as to obtain a proper press-formed quality.;COPYRIGHT: (C)1996,JPO