Machine tool comprising a tool driven in the axial direction by a hydraulic lifting cylinder, in particular a gear shaper machine
AssigneeMannesmann Rexroth GmbH
InventorAlfred Feuser
Life of this patent
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Abstract
A machine tool comprising an axially reciprocating tool is driven by a hydraulic jack or lifting cylinder which is controlled by a servovalve. The amplitude and velocity of the lifting cylinder is set at a control circuit to which the position and acceleration of the lifting cylinder are applied as input variables. The electrohydraulic control has a high damping and high gain. As a result the velocity change of the lifting cylinder when the tool enters the workpiece is negligibly small.
Claims10
In a machine tool comprising a tool driven in the axial direction by a piston of a hydraulic lifting cylinder and a directional valve for controlling the fluid paths between said cylinder, a fluid source and a reservoir for actuating said piston, characterized by a position pickup for electronically detecting the position of said piston, said directional valve comprising an electrically operated servovalve driven by a controller, said controller being programmed for processing the actual value of the piston position as sensed in said position sensor, a desired value for th piston position and a desired value for the duration and frequency of the stroke of piston for operating said servovalve to achieve said desired value of duration and frequency of piston stroke.
Dependencies are inferred from the claim text.