To provide a pressing mechanism which reduces nonuniformity on the occasion of pressing an object, prevents pollution due to a hydraulic fluid and also enables attainment of miniaturization.
The pressing mechanism is equipped with a hydraulic fluid source 2 wherein hydraulic fluid 1 is stored, a first sub-cylinder 4, a supply passage 3 making the hydraulic fluid source 2 and the first sub-cylinder 4 communicate with each other, a main cylinder 6 communicating with the hydraulic fluid source 2 through the intermediary of the supply passage 3 and a check valve 5, a main piston 18 provided inside the main cylinder 6, a discharge passage 7 making the main cylinder 6 and the hydraulic fluid source 2 communicate with each other, a supply control valve 22 and a discharge control valve 25 provided respectively for the supply passage 3 and the discharge passage 7, a first sub-piston 10 pressing the hydraulic fluid 1 in the first sub-cylinder 4, a pressing plate 11 pressing the first sub-piston 10, a second sub-cylinder 13, a second sub-piston 15 pressing the pressing plate 11 through the intermediary of the hydraulic fluid in the second sub-cylinder 13, and a first piezoelectric element 16 displacing the second sub-piston 15.
TAKEHARA KATSUNAO