Hydraulic circuit diagram extrusion press

Fig. 72 shows the hydraulic circuit diagram of an extrusion press operated from a pressure water accumulator. The press has separate controls for the piercing- and main cylinders. When w orking without piercer, the control lever of the piercer control is set to return. When the lever of the main control is shifted to advance, the filling water flows from the air-vessel through the filler valve into the main cylinder and through... 

Fig. 82 illustrates the hydraulic circuit diagram of an oil-hydraulic extrusion press operated by a variable-delivery pump (see p. 212). The control stand accommodates a hand-wheel connected linkage which sets the press to advance or return, as well as two rotary slide valves which serve to lock and shift the die-carrier with the die. The linkage acts on a servo-control (see p. 215), which is arranged directly at the pump the servo-control is connected to a geared pump, also called pilot pressure pump. 

Fig. 82. Hydraulic circuit diagram of an oil-hj draulic extrusion press...

The operation of a tube extrusion press as per Fig. 89, may be followed best by reference to a hydraulic circuit diagram. Fig. 92. The idle stroke is not performed by an advance piston, but by low-pressure or filling water of relatively high pressure. 

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