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.

A wire electrical discharge machine includes: a detection unit configured to detect a contact state in which the wire electrode contacts the workpiece, and a contact release state in which the wire electrode that is in the contact state is separated from the workpiece; a vibration unit configured to, if the contact state is detected during the machining of the workpiece, stop relative movement of the wire electrode and vibrate the wire electrode about a stop position at which the relative movement of the wire electrode has been stopped; and a relative movement control unit configured to resume relative movement of the wire electrode if the contact release state is detected until a predetermined time elapses from when the contact state has been detected or until the number of times that the wire electrode is vibrated reaches a predetermined number of times.

A wire electrical discharge machine for machining a workpiece by generating electric discharge at a discharge gap between the workpiece and a wire electrode includes: a machining current setting unit for setting the magnitude of a normal machining current depending on the discharge gap state at application of a discharge induction voltage at the previous time or previous times; and a machining current control unit configured to control a main discharge circuit so as to supply the normal machining current to the discharge gap when the present discharge gap state is the normal state, control the main discharge circuit so as to supply a short-circuit machining current smaller than a predetermined current to the gap when the discharge gap state is the short-circuited state, and control the main discharge circuit so as not to supply any machining current to the gap when the discharge gap state is the open state.

The disclosure provides a wire electric discharge machine which has a simple configuration and can make a wire electrode fed to a machining position rotate around an axis. The wire electric discharge machine for machining a workpiece includes an upper wire guide and a lower wire guide, which stretch a wire electrode therebetween, and a rotator. A position of the rotator is changed, whereby the wire electrode is rotated around an axis.

A control device of a wire electric discharge machine and a machine learning device are provided that can appropriately and readily determine a correction parameter. The control device, which optimizes the correction parameter for wire electrical discharge machining process, includes a machine learning device configured to learn the correction parameter for the wire electrical discharge machining process. The machine learning device includes a state observation unit configured to observe, as a state variable, condition data indicative of a condition for the wire electrical discharge machining process, a determination data acquisition unit configured to acquire determination data indicative of the correction parameter of the case where machining precision is favorable in the wire electrical discharge machining process, and a learning unit configured to learn the correction parameter in association with the condition for the wire electrical discharge machining process using the state variable and the determination data.

A wire electrical discharge machine includes a first voltage applying circuit, a second voltage applying circuit, and a switch controller. The first voltage applying circuit includes a first DC power source for applying a positive polarity voltage across an electrode gap, and a first switch for on/off-switching of application of the positive polarity voltage. The second voltage applying circuit includes a second DC power source for applying a reverse polarity voltage to the electrode gap, and a second switch for on/off-switching of application of the reverse polarity voltage. The switch controller controls the first switch and the second switch so that the first switch and the second switch are not turned on simultaneously. The first DC power source and the second DC power source are set up so that the absolute value of the reverse polarity voltage is lower than the absolute value of the positive polarity voltage.

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.

The wire electric discharge machining device includes a wire bobbin configured to wind and hold a wire electrode, a wire delivery roller configured to draw the wire electrode from the wire bobbin and deliver the wire electrode continuously toward a work-piece, a brake motor configured to apply a load to the wire bobbin in a direction against the drawing of the wire electrode, rotation speed detector configured to detect a rotation speed of the wire bobbin, an emptiness determination device configured to determine that the wire bobbin reaches an empty state based on a rapid change in the rotation speed of the wire bobbin detected by the rotation speed detector, and a drive control part configured to stop the drive of the wire delivery roller when the emptiness determination device determines that the wire bobbin reaches the empty state.

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.

An electrical machining method comprises machining a workpiece by an electrical machining device comprising an electrode; increasing a feedrate of the electrode at a first acceleration if a discharge current passing through the electrode and the workpiece is lower than a discharge current reference; and decreasing the feedrate of the electrode at a second acceleration if the discharge current is higher than the discharge current reference, wherein the second acceleration has an absolute value higher than that of the first acceleration.