Inventors:
Delbert E. Lucas - Fairfield OH
Stephen J. Lieland - Lawrenceburg IN
Assignee:
Cincinnati Incorporated - Cincinnati OH
International Classification:
F15B 1110
Abstract:
A control system for controlling the movement of the slide of a hydraulic press of the type having a main cylinder containing a piston mounting the slide. The control system comprises an electronic processor, a pressure transducer to measure the pressure of hydraulic fluid applied to the piston to move the slide downwardly, a position encoder coupled to the slide to determine the vertical position of the slide, and a hydraulic circuit to supply hydraulic fluid under pressure to the cylinder to move the piston and slide upwardly and downwardly. The hydraulic circuit comprises a plurality of cartridge valves having controls actuable by outputs from the processor. The processor is capable of handling inputs, including inputs from the pressure transducer and position encoder, and outputs to control the hydraulic circuit to shift the slide upwardly and downwardly at different preselected speeds, to reverse downward travel of the slide at a preselected point based on either slide position or tonnage applied by the slide to a workpiece, and to adaptively optimize decompression of the hydraulic fluid in the hydraulic system at the end of downward movement of the slide.