| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable a press cylinder to operate in two modes, namely a formation mode and a finish mode in which the press cylinder acts at a higher pressing capacity than in the formation mode. SOLUTION: The action of a press cylinder 5 is controlled by means of a valve 29 for operating the press cylinder 5, with pressure oil drawn from an oil tank 28 by means of an oil pump 27, and the action of an extrusion cylinder 8 is controlled by means of a valve 30 for operating the extrusion cylinder 8. A relief valve 31 acting at a set (low) pressure in the formation mode and a relief valve 32 acting at the maximum (high) pressure in the finish mode are connected in parallel to the press cylinder 5. A shutoff valve 35 is connected in series to the relief valve 31 and the action of the press cylinder 5 is changed over between the formation mode and the finish mode by operating the shutoff valve 35.</p> |
