| 摘要 |
PURPOSE:To simplify and make the structure of a device more compact and of less weight by setting the sum of the effective pressurized area of the front section of a clamping ram and the effective area of the front of an auxiliary piston equal to the effective pressurized area of the clamping ram rear section. CONSTITUTION:A front section oil chamber (chamber A) and a rear section oil chamber (chamber B) of a clamping cylinder 28 and a front section oil chamber (chamber E) of an auxiliary cylinder 29 are communicated with each other by an oil line 36. As the sum of effective pressurized area of a front section of a clamping ram and a section effective pressurized area of the front of an auxiliary piston is set equal to a rear section effective pressurized area of a clamping ram, the volume of oil discharged from the chambers A and E and fed to the chamber B, and the volume of oil necessary for the chamber B are equal, when a movable platen 20 and an auxiliary piston 34 are linked together at the time of high speed mold closing, and the chamber B never gets negative pressure. After the linking of the chamber B is closed by an on-off means, high pressure clamping is carried out by feeding hydraulic oil into the chamber B. By said arrangement, the inside of the rear oil chamber of the clamping cylinder never gets negative pressure at the time of high speed mold closing, and pressure rising in heavy clamping can be carried out in a short period of time. Furthermore, the overall length can be shortened to make a device more compact, of less weight and less expensive. |
