| 摘要 |
1,263,490. Extruding. ALLMANNA SVENSKA ELEKTRISKA A.B. 1 July, 1969 [2 July, 1968], No. 33075/69. Heading B3P. A hydrostatic extrusion apparatus comprising a pressure chamber 3, a plunger 12 and an operating cylinder 2 has a position indicator 30 for the plunger, a pressure indicator 28 for the cylinder and a calculator 34 to receive signals from the indicators and to sense when the extrusion starts and to interrupt the extrusion when the billet is almost completely extruded. The calculator is calibrated using a billet of known volume and with no billet in the pressure chamber. During operation the signals from the indicators are compared in the calculator with the calibrated values. The calculator may be digital or analogue and control one or more presses. The extrusion pressure fluid for the cylinder 2 is supplied through a solenoid valve 21. In operation the start of the extrusion (S 1 ), Fig. I (not shown), is signalled to the calculator which calculates the distance the plunger 12 is allowed to travel into the chamber 3. The valve is moved to either interrupt the pressure supply or to unload the cylinder 2 to allow the plunger to recoil. |
