A power supply device for an electric discharge machine includes a DC power supply which is connected in parallel to an electrode gap, a plurality of switching elements which are in parallel to each other and which are arranged between the electrode gap and the DC power supply, a current value acquisition unit for acquiring a value of a current, and an ON-OFF control unit which, during the time when the current value reaches a predetermined value until the time when the current starts to fall, sets a cycle for switching the plurality of switching elements from off to on to the same cycle, switches the plurality of switching elements from off to on in a predetermined order for each timing of a phase of 90°, which is 360° divided by the number of the plurality of switching elements, sets an ON-period of each of the plurality of switching elements based on a difference between the value of the current and the predetermined value, and performs ON-OFF control of the plurality of switching elements based on the cycle, the timing, and the ON-period.

A power supply device for an electric discharge machine includes a DC power supply which is connected in parallel to an electrode gap, a plurality of switching elements which are in parallel to each other and which are arranged between the electrode gap and the DC power supply, a current value acquisition unit for acquiring a value of a current, and an ON-OFF control unit which, during the time when the current value reaches a predetermined value until the time when the current starts to fall, sets a cycle for switching the plurality of switching elements from off to on to the same cycle, switches the plurality of switching elements from off to on in a predetermined order for each timing of a phase of 90°, which is 360° divided by the number of the plurality of switching elements, sets an ON-period of each of the plurality of switching elements based on a difference between the value of the current and the predetermined value, and performs ON-OFF control of the plurality of switching elements based on the cycle, the timing, and the ON-period.

A wire electrical discharge machine includes: a pulse detection unit configured to detect voltage pulses repeatedly applied between a workpiece and a wire electrode; an instability calculation unit configured to calculate the degree of instability indicating how unstable the discharge state is, by using the number of non-discharge pulses that present no voltage drop due to electrical discharge, among the pulses detected per unit time by a pulse detection unit; and a machining condition changing unit configured to change a machining condition for the workpiece, based on the calculated degree of instability.

A wire electrical discharge machine includes: a pulse detection unit configured to detect voltage pulses repeatedly applied between a workpiece and a wire electrode; an instability calculation unit configured to calculate the degree of instability indicating how unstable the discharge state is, by using the number of non-discharge pulses that present no voltage drop due to electrical discharge, among the pulses detected per unit time by a pulse detection unit; and a machining condition changing unit configured to change a machining condition for the workpiece, based on the calculated degree of instability.

An electro-hydraulic joint supplying system for electrical machining and supporting automatic tool changing includes an electro-hydraulic joint supplying device and a clamping device. The electro-hydraulic joint supplying device includes an insulator, an electro-hydraulic joint supplying base, an electro-hydraulic joint supplying pipe terminal, and an electro-hydraulic joint supplying pipe. The base is fixedly connected with a spindle shell through the insulator. A working fluid pipe connector and a wiring post are arranged on the base; a terminal connector is in a snap-fit with a top end of the electro-hydraulic joint supplying pipe terminal. The pipe terminal communicates with a flushing fluid container in an electrical machining electrode shank through an electro-hydraulic joint supplying pipe. The clamping device includes a first clamping mechanism, a second clamping mechanism, and a cooperation mechanism fixedly connected with the first clamping mechanism or the second clamping mechanism to circumferentially limit the flushing fluid container.

An electro-hydraulic joint supplying system for electrical machining and supporting automatic tool changing includes an electro-hydraulic joint supplying device and a clamping device. The electro-hydraulic joint supplying device includes an insulator, an electro-hydraulic joint supplying base, an electro-hydraulic joint supplying pipe terminal, and an electro-hydraulic joint supplying pipe. The base is fixedly connected with a spindle shell through the insulator. A working fluid pipe connector and a wiring post are arranged on the base; a terminal connector is in a snap-fit with a top end of the electro-hydraulic joint supplying pipe terminal. The pipe terminal communicates with a flushing fluid container in an electrical machining electrode shank through an electro-hydraulic joint supplying pipe. The clamping device includes a first clamping mechanism, a second clamping mechanism, and a cooperation mechanism fixedly connected with the first clamping mechanism or the second clamping mechanism to circumferentially limit the flushing fluid container.

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 performs electrical discharge machining on a workpiece by applying voltage across an electrode gap formed between a wire electrode and the workpiece to thereby generate electrical discharge while moving the wire electrode relative to the workpiece along a path specified by a machining program. The wire electrical discharge machine includes: a voltage detector for detecting a gap voltage across the gap; a facing area calculation unit for calculating, as a facing area, the area of a surface of the workpiece contained within a predetermined distance from the center axis of the wire electrode; an axis feed rate determination unit for determining an axis feed rate based on the gap voltage value detected by the voltage detector, and the facing area; and a movement control unit for performing control so that the wire electrode moves relative to the workpiece at the axis feed rate.

A wire electrical discharge machine performs electrical discharge machining on a workpiece by applying voltage across an electrode gap formed between a wire electrode and the workpiece to thereby generate electrical discharge while moving the wire electrode relative to the workpiece along a path specified by a machining program. The wire electrical discharge machine includes: a voltage detector for detecting a gap voltage across the gap; a facing area calculation unit for calculating, as a facing area, the area of a surface of the workpiece contained within a predetermined distance from the center axis of the wire electrode; an axis feed rate determination unit for determining an axis feed rate based on the gap voltage value detected by the voltage detector, and the facing area; and a movement control unit for performing control so that the wire electrode moves relative to the workpiece at the axis feed rate.

A drive circuit configured to drive a load. The drive circuit comprises a transformer. The transformer comprises a transformer primary comprising one or more primary windings connected to arms that pass through a magnetic material. The transformer also comprises a transformer secondary comprising secondary windings connected to planar secondary conductors which pass through the inside of the arms. The drive circuit also comprises a voltage source configured to apply a voltage across the transformer primary.