| 摘要 |
PURPOSE:To enable a single cylinder to perform the respective functions or the sealing of vent, cutting of gate and ejection of product by a method wherein the piston of a foremost stage is advanced stepwise by successively actuating an ejection cylinder by means of a plurality of pistons and at the same time reciprocated a plurality of times. CONSTITUTION:First, when injection process is started, a solenoid SOL (A) is actuated so as to change over the valve position of a change-over valve to the B side in order to supply working oil to a space part 5a. As a result, a piston 2a is advanced and similarly a piston 2c is also advanced by the prede termined stroke integrally with the piston 2a so as to seal a vent by blocking a vent groove 3 with a vent-sealing end 28a. Secondly, simultaneously with the finish of injection, the solenoid SOL (B) of a change-over valve 14 is actuat ed so as to advance the piston 2c by pressing it with a piston 2b and consequent ly a plate 27 in a mold further advances so as to cut off a gate part 33 with a gate cutting end 29a. |
