| 摘要 |
<p>PURPOSE:To enable optional change of a pressure reducing pattern by providing a reciprotating type pressure intensifier to to a cold hydrostatic press forming device and using said pressure intensifier as a displacement-type pressure reducer. CONSTITUTION:Pressure oil is fed into the right and left cylinders of a double- action type hydraulic cylinder mechanism 5 provided to a reciprocating type pressure intensifier 4 by changing over a valve 19 to force the plungers 25, 24 of cylinder mechanisms 9, 8 for pressure medium via plungers 15, 14. When a piston 13 moves right, the pressure medium forces a check valve 31 to open then the pressure medium is fed through a feed port 3 to a high pressure forming vessel 1 thereby forming a material 2 with the hydrostatic pressure. On the other hand, the cylinder of the mechanism 8 is brought under the negative pressure and sucks the pressure medium in a tank 28 connected thereto by forcing a check valve 26 to open. When the piston 13 moves left, the mechanisms 9, 8 act respectively to suck and discharge the pressure medium. The pressure medium in the vessel 1 is thus reduced in pressure. The forming pressure is detected with a detector 34 in this stage and is compared with a set value. Said value is fed back to a solenoid operated relief valve 41 to regulate the set pressure thereof by which the desired regulation of the speeds of the plungers 24, 25 is made possible.</p> |
