초록 ▼

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 m

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.

대표청구항 ▼

A control system for controlling the movement of the slide of a hydraulic press of the type having a main cylinder, a piston in said cylinder, a slide for applying tonnage to a workpiece, said piston mounting said slide, workpiece contacting tool means on said slide, at least one volume in said cyli

A control system for controlling the movement of the slide of a hydraulic press of the type having a main cylinder, a piston in said cylinder, a slide for applying tonnage to a workpiece, said piston mounting said slide, workpiece contacting tool means on said slide, at least one volume in said cylinder above said piston and a volume in said cylinder below said piston, a reservoir for hydraulic fluid to activate said main cylinder, a hydraulic circuit between said main cylinder and said reservoir for supplying hydraulic fluid under pressure to said cylinder to shift said piston and slide upwardly and downwardly, and a high volume pump and a low volume pump to supply hydraulic fluid under pressure from said reservoir to said hydraulic circuit, said control system comprising an electronic processor having inputs and outputs to control said hydraulic circuit in accordance with a preprogrammed routine, a pressure transducer positioned to measure and provide an output representative of the pressure of hydraulic fluid supplied to said cylinder by said hydraulic circuit to shift said piston and slide downwardly and thus representative of the tonnage applied by said slide against a workpiece, a position encoder coupled to said slide to provide an output indicating the vertical position thereof, said outputs of said pressure transducer and said position encoder being connected to the inputs of said processor, and said hydraulic circuit comprising a plurality of cartridge valves having control means actuable by outputs of said processor, said hydraulic circuit also including a cartridge valve between said volume below said piston and said reservoir serving as a counter-balance valve to maintain a threshold pressure in said volume below said piston to support the weight of said piston, slide, and tool means, said counter-balance cartridge valve being controlled by hydraulic fluid pressure directed to and exiting from said volume below said piston, and a prefill poppet valve between said at least one volume above said piston and said reservoir said prefill poppet valve being controlled by hydraulic pressure both below and above said piston.