Method for electrical discharge machining
AssigneeAgie Charmilles SA
InventorMarco BOCCADORO
Life of this patent
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Abstract
A method for electrical discharge machining (EDM) a workpiece by means of a train of machining pulses. During the machining time the machining pulses are applied to the working gap between workpiece and electrode. An open voltage is first applied, the ignition delay time td is measured, then, at the beginning of the discharge, its fall time tf is measured, and certain shape features (e.g. the pedestal and ramp) of the pulse are adapted in real time for the very same discharge, as a function of said ignition delay time and/or fall time. Moreover, instead of shaping the very same discharge, one or more subsequent discharges can be shaped as a function of td and/or tf of a single discharge, or of an average of td and/or tf over several discharges.
Claims16
A method for electrical discharge machining of a workpiece by a tool electrode, wherein a plurality of discrete electrical discharge machining pulses are applied to a gap between the work piece and the tool electrode, comprising wherein,
- an open voltage Uo is applied between the electrode and the work piece to induce a discharge;
- a gap voltage UGap is measured;
- at least one time parameter related to the gap voltage is computed,
- a shape characteristics of a current pulse is determined based on the determined at least one time parameter, and
- the current pulse is generated according to the determined shape characteristics and applied to the tool electrode.
A machine tool for electrical discharge machining of a workpiece by a tool electrode including a power generator and a control unit, wherein a plurality of discrete electrical discharge machining pulses are applied to a gap between the work piece and the tool electrode, comprising wherein, an open voltage Uo is generated by the power generator and applied between the electrode and the work piece to induce a discharge;
- a gap voltage UGap is measured;
- at least one time parameter related to the gap voltage is computed by the control unit,
- a shape characteristics of a current pulse is determined based on the determined at least one time parameter by the control unit, and
- the current pulse is generated according to the determined shape characteristics and applied to the tool electrode.
Dependencies are inferred from the claim text.