To stably grip a hydraulic actuation device and efficiently carry out open and close operation of an actuation tool even if a strong force acts thereon.
A spool valve 24 is slidably arranged in a direction crossing a piston rod 18 at right angles. A cylindrical grip handle 34 gripped by a hand of an operator is attached outside of a main body casing 5 in parallel with the piston rod 18. The grip handle 34 is rotatable around an axis of the grip handle 34. The spool valve 24 and the grip handle 34 are connected via cam mechanisms 29, 30, 31. The spool valve 24 is moved up and down by rotating the grip handle 34 to control hydraulic fluid flow.
Next Patent: OPTICAL MICROPUMPS