To provide a ram driving method in a hydraulic press capable of switching the ram lowering speed to the approaching speed or the pressing speed without any delay, and an apparatus thereof.
When a ram 5U is lowered during the pressing operation, the ram is rapidly lowered at the approaching speed according to a pattern preset by an upper part table speed distribution unit 63, and a speed switching valve 45 is switched by the command from a speed switching command unit 65, and the ram is lowered at the pressing speed to perform the pressing. A switching command timing determination unit 67 determines the deceleration starting time at the approaching speed as the switching command timing, a switching command is given to the speed switching valve 45 by the speed switching command unit 65, and the speed is transferred to the pressing speed after finishing the approaching speed.
WO/2017/186712 | HYDRAULIC SPINDLE FOR A PRESS |
JP3366560 | [Title of Invention] Press Machine |
AMADA CO LTD