PRESS WORKING METHOD OF PRESS MACHINE AND PRESSING PRESSURE INCREASING DEVICE OF PRESS MACHINE USED FOR THIS

摘要

PURPOSE:To make possible pressing beyond the maximum capacity of the press machine by increasing the pressing pressure of its ram by a force doubler, pushing down a movable working frame by this force and pressing the work. CONSTITUTION:A pressing pressure increasing device 23 is placed on the bed 25 of a press machine 24 and a stationary working table 3 is fixed to the bed by means of a clamper 26. The work 27 is placed on the stationary working table and the press machine is operated. Every time when the ram 28 of the press makes one reciprocation, a movable working frame 5 makes one reciprocation by way of a hydraulic pressure doubler 10 and at the descending of the ram, it pushes down a plunger 13. Because of this, the plunger goes into a hydraulic fluid chamber 15 and a piston 12 is forced down by as much as the volume portion that it entered. Since the piston has a sectional area ratio of 5:1 with respect to the plunger, its descending is 1/5 time and the pressing pressure becomes five times. Namely, the movable working frame presses the work under pressure 5 times the maximum pressure of the ram.