| 摘要 |
PURPOSE:To prevent the generation of an overweight, a burr or a sink mark, by sampling final filling pressure in a filling process only for a predetermined time by a pressure holding process change-over signal and holding the holding pressure of the first stage in a pressure holding process to the final filling pressure only for a predetermined time. CONSTITUTION:When a pressure holding process change-over signal is issued, a relay 11R is operated and a contact 11R1 is connected to perform the sampling of pressure for the time set to a timer T1. At the same time, a change-over apparatus 17 is connected to a hold circuit 18 for the time set to a timer T2. Therefore, the output from an amplifier 11 comes to an F/B signal and a protruded output value F/B=HOLD at a matching point 20 and acted on a drive part 12 through a change-over apparatus 16. When the time set to the timer T2 is elapsed, the change-over apparatus 17 is connected to a pressure holding control circuit 14. The output signal REF from CPU is connected to the matching point 20 as the holding pressure of a second stage through a change- over apparatus 15, the pressure holding control circuit 14 and the change-over apparatus 17 and the output of the amplifier 11 comes to F/B=REF to be outputted to the drive part 12. |
