| 摘要 |
<p>A free-piston engine having a fluid energy unit comprises a cylinder (1) and a piston (2) reciprocating within the cylinder (1). The piston (2) is equipped with a plunger-shaped extension (10) including a first axial face (50) moving within a chamber (30) when the piston (2) is moved. There are provided supply means (42, 43) for supply of liquid from a supply reservoir (34) to the chamber (30) and discharge means (36-40) for discharge of fluid from the chamber to an accumulator (33). The plunger-shaped extension (10) further comprises an axial face (49) opposite to the first axial face (50) and bordering a pressurized room (31) in the top dead centre of the piston (1). The hydraulic unit further includes a compression section (20) for making a compression stroke of the piston (1). The discharge means (36-40) include separate first and second discharge channels (37, 38) of which the first discharge channel (37) connects to the chamber (30) in such manner that a discharge of liquid from the chamber (30) to the accumulator (33) can take place only in a first part of the expansion stroke of the piston (1) and the first discharge channel (37) having a low flow resistance, the second discharge channel (38) connecting to a pressurized room in such manner that a discharge of liquid from this room to the accumulator can take place in a last part of the expansion stroke of the piston (2) and the second discharge channel (38) including a quickly closing non-return valve preventing a flow of liquid to the pressurized room.</p> |
