A machining method for three-dimensional open flow channel using high-speed arc discharge layered sweep, which arranges an axial line of an installation shaft of a tool electrode with six degrees of freedom to be perpendicular to an axial line of a to-be machined work piece in an arc discharge process, with the tool electrode sweeping in a closed path in a plane or a curved surface perpendicular to the installation shaft, wherein the path of the sweeping satisfies: a space of an enveloped space being formed by the tool electrode moving in the path and being coincident with a removed portion of the work piece does not exceed a preset machined cavity of the flow channel. The present invention is based on high-speed arc discharge of hydrodynamic arc breaking and realized layered milling and surface machining for three-dimensional open flow channels.

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.

In a wire electric discharge machine, time from application of a voltage to a machining gap between a workpiece and a wire electrode until occurrence of electric discharge is measured as a discharge delay time, and the measured discharge delay time is integrated over a predetermined measurement period to calculate a discharge delay integrated time. Further, the number of times of the voltage application in the measurement period is counted. An average discharge delay time per voltage application in the measurement period is calculated from the discharge delay integrated time and the number of times of voltage application. The movement of the wire electrode with respect to the workpiece is controlled on the basis of the average discharge delay time.

An electrical discharge machining device provided, using a floating capacitance to provide a machining target with improved surface roughness. An electrical discharge machining device 1 includes a current supply circuit 3 that supplies a current to a gap between an electrode 17 and a machining target 19 so as to provide electrical discharge machining. A floating capacitance portion 21 occurs between the electrode 17 and the machining target 19 in the electrical discharge machining. The floating capacitance portion 21 supplies its stored charge to the gap in the electrical discharge machining. A capacitor 11 stores a charge before the floating capacitance portion 21 is discharged. After the floating capacitance portion is discharged, the capacitor 11 charges the floating capacitance portion 21. The floating capacitance portion 21 is discharged again after it is charged. Such an operation generates a pulse current, thereby providing electrical discharge machining.

An electrical discharge machining device is provided, using a floating capacitance to provide a machining target with improved surface roughness. An electrical discharge machining device 1 includes a current supply circuit 3 that supplies a current to a gap between an electrode 17 and a machining target 19 so as to provide electrical discharge machining. A floating capacitance portion 21 occurs between the electrode 17 and the machining target 19 in the electrical discharge machining. The floating capacitance portion 21 supplies its stored charge to the gap in the electrical discharge machining. A capacitor 11 stores a charge before the floating capacitance portion 21 is discharged. After the floating capacitance portion is discharged, the capacitor 11 charges the floating capacitance portion 21. The floating capacitance portion 21 is discharged again after it is charged. Such an operation generates a pulse current, thereby providing electrical discharge machining.

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.

A method of yielding a thinner product wafer from a thicker base SiC wafer cut from a SiC ingot includes: supporting the base SiC wafer with a support substrate: and while the base SiC wafer is supported by the support substrate, cutting through the base SiC wafer in a direction parallel to a first main surface of the base SiC wafer using a wire as part of a wire electrical discharge machining (WEDM) process, to separate the product wafer from the base SiC wafer, the product wafer being attached to the support substrate when cut from the base SiC wafer.

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.

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.