Patent ID: 6851355

Claim:
A method for pressing an object with a main piston placed in a main cylinder by means of applying a prescribed pressure to said main piston with working fluid wherein: said working fluid is compressed to said prescribed pressure by supplying said working fluid to said main cylinder with driving power of a piezoelectric element, said prescribed pressure is applied through a piping system that includes said main cylinder, a supply line and a discharge line of said working fluid with respect to said main cylinder, a check valve preventing reverse flow of said working fluid from said main cylinder to said supply line, and a sub-cylinder provided within said supply line, said method comprises: a first step of displacing a sub-piston provided within said sub-cylinder from an initial position to press said working fluid such that said working fluid is introduced via said main piston provided within said main cylinder; and a second step of causing said sub-piston to return to said initial position such that said working fluid is supplied to said sub-cylinder, said first step and said second step are repeated successively until a pressure of said working fluid in said main cylinder reaches said prescribed pressure, said first step is performed in a state in which a discharge control valve disposed in said discharge line and a supply control valve disposed in said supply line are closed, said second step is performed in a state in which said discharge control valve and said check valve are closed and said supply control valve is open, said supply control valve, said discharge control valve and said sub-piston each respectively have a respective said piezoelectric element attached thereto, and said piezoelectric elements serve to open and close said supply control valve and said discharge control valve, and to displace said sub-piston from the initial position, respectively.