Abstract: A computerized die-casting machine control includes a microcomputer and a programmable controller having presettable inputs to establish a desired machine operating sequence. Temperature sensors at the holding furnace, cover die, ejector die, gate and at the die impact bushing monitor the die casting variables and produce input signals to the shot-control micro-computer. The micro-computer is programmed to take pre-programmed actions to correct out of tolerance conditions in the machine on a continuous on-line basis during machine operation.

Abstract: A die casting machine has a hydraulic shot ram controlled by a servo system that includes pre-settable thumbwheel switches to establish a desired memory of shot speed values and shot position presets in a programmable computer. An analog output responsive to the control program in the programmable computer produces a direct current analog velocity command signal. A servo amplifier includes means for comparing the command analog signal and a feedback signal from transducers sensing velocity of the hydraulic ram and position of valve means to produce an on-off servo valve signal so that a servo valve will modulate flow from a third state Olmsted shot valve so as to compensate for shot speed changes produced by changes in operational conditions including wear and build-up on a cylinder and ram; hydraulic oil heat-up during operation of the machine; and changes in flow characteristics of a molten metal due to temperature variations thereof.