A wire electrical discharge machine includes: a gap voltage detector for detecting a voltage across an electrode gap; a first voltage control unit for applying a first voltage to the electrode gap; a discharge determiner for determining whether or not the electrode gap is in a discharging state during application of the first voltage; and a second voltage control unit for supplying a machining current through the electrode gap when the electrode gap is in a discharging state. After a supply of the machining current to the electrode gap, even when a discharge is induced by the next application of the first voltage to the electrode gap, the second voltage control unit prohibits application of a second voltage to the electrode gap.

A device for machining a part (8) by electrical discharge machining using an electrode wire (4), comprising: means (20, 30, 60) for holding the electrode wire (4) taut and driving it to translate longitudinally, in proximity to said part (8) to be machined, in a sparking zone (5), means (50) for making a stream of dielectric liquid flow through the sparking zone (5) between the electrode wire (4) and the part (8) to be machined, an electrical power source (10) for generating electrical pulses that cause sparks in the sparking zone (5) between the electrode wire (4) and the part (8) to be machined, controlling means (40) that control the device depending on the machining parameters, measuring means (70) for evaluating the quantity of gas bubbles present in the sparking zone (5) between the electrode wire (4) and the part (8) to be machined, and for delivering to the controlling means (40) a signal (73) representative of said quantity of gas bubbles, in the controlling means (40), adapting means (41) for modifying the machining parameters, so as to maintain the value of said signal (73) within a suitable range of signal values.

An online prediction method of tool-electrode consumption adapted for an electrical discharge machining (EDM) apparatus includes an experimental design; extracting electrode consumption variables from machining parameters of the electrical discharge machining (EDM) apparatus; and obtaining a correlation between the machining parameters and the electrode consumption variables through a correlation analysis to obtain a prediction model capable of predicting an effective contact area of a tool-electrode and a workpiece. In addition, a prediction method of machining accuracy is provided.

The object of the present invention is to make it possible to maintain a stable electric discharge and to achieve a stable quality and machining performance even when a work having a non-uniform composition is machined. A wire electric discharge machining device performs electric discharge machining on a work while controlling an inter-electrode distance between a wire and the work based on an inter-electrode voltage between the wire and the work so as to match a set target voltage. The wire electric discharge machining device includes an inter-electrode voltage measuring unit that measures the inter-electrode voltage, an actual amplitude calculating unit that calculates an amplitude of the measured inter-electrode voltage, and a target voltage correcting unit that corrects the target voltage in such a way that the calculated amplitude approaches the target amplitude that is set to a value larger than zero.

A wire electric discharge machine configured to interrupt a program operation if a connection hole for connecting a wire electrode is located in a position deviated from a wire electrode connection position on a machining path so that connection by a wire electrode connection unit is not completed and store the wire electrode connection position, and to restart the program operation after performing machining such that the wire electrode is returned to the wire electrode connection position by automatic control and machining to widen a machined groove portion in the wire electrode connection position, when subjected to a re-machining operation after manual connection of the wire electrode in the position of the connection hole.

A wire electric discharge machine provided with a disconnection repairing unit includes a core-fixing-end-position storing unit for storing a core fixing end position of a depositing and accumulating operation machined most lately among positions at which the depositing and accumulating operation for machining wastes by a core fixing function ends in a machining shape currently being machined and a disconnection repairing unit for executing automatic connection between a disconnection position and the core fixing end position.

The specification discloses an electrical discharge machining (EDM) system and method capable of defining an unlimited number of waveforms. The system and method define logical waveforms using a plurality of time slices, each having a voltage and a width. The time slices are applied to the system power section where they are amplified and delivered to the electrode.

Whether or not an inter-electrode voltage exceeds a voltage threshold is determined after a predetermined inter-electrode state determination period has passed since application of an induction voltage (inter-electrode voltage) to an inter-electrode gap. Thus, an inter-electrode gap amount between a wire electrode and a work is estimated. A pause time during which electrical discharge is not performed is changed according to an estimation result of the inter-electrode gap amount.

The present invention is a power supply control apparatus that controls pulse discharge occurring in a machining gap in an electric discharge machine. The power supply control apparatus includes: a voltage level detecting device that detects the voltage level of a discharge voltage generated in the machining gap; a voltage level comparator hat compares the voltage level with a voltage level reference value, and outputs a comparison result; and a determining unit that, on the basis of the comparison result, determines whether a discharge pulse is abnormal in a designated one of a plurality of determination modes. The determination method can be designated during machining.

A method for electrical discharge machining a work piece using rectangular processing pulses includes forming the rectangular processing pulses by discharging one or multiple discrete delay lines that comprise multiple storage elements. The storage elements are arranged as part of a feed line to a spark gap on a section of the feed line near the spark gap. The discrete delay lines are connected to a guide head by an electrode-side contact unit and are connected to the work piece by a work piece-side contact unit.