A wire electrical discharge machine controls a second motor unit including motors for feeding a wire electrode in a wire running direction in which the wire electrode extends, so as to feed the wire electrode at a set feed rate during a machining period from a first time point at which the wire electrode moving relative to a workpiece in a direction intersecting the wire running direction is estimated to enter the workpiece, to a second time point at which the wire electrode is estimated to exit the workpiece. The second motor unit is controlled so as to feed the wire electrode at a feed rate lower than the set feed rate during at least one of a first non-machining period from a processing start time point to the first time point and a second non-machining period from the second time point to a processing end time point.

A wire electrical cutting machine for machining a circular part by a wire electrode.

A power supply system for wire electric discharge machining includes a first power supply circuit and a second power supply circuit. The first power supply circuit applies, to the machining gap, a voltage that induces a discharge. The second power supply circuit, which includes a low inductance line, supplies a current, which contributes to the machining, to the machining gap,. A blocking diode is series-connected between the low inductance line and the machining gap. A container, which has a contact surface contacting with the blocking diode and contains a cooling liquid, is provided.

A wire cut electric discharge machining apparatus cannot maintain high machining accuracy because the arm may expand/contract as it receives more heat from the machining fluid. The wire cut electric discharge machining apparatus has guide parts that guide a wire and arms that support the guide parts, wherein at least one of the guide parts has a machining fluid ejection nozzle, and at least one of the arms has an ejection connection pipe and a thermal insulation part. The ejection connection pipe is a hole penetrating the arm and supplies the machining fluid to the machining fluid ejection nozzle, and the thermal insulation part covers the inner peripheral surface of the ejection connection pipe to thermally insulate the inner hole of the ejection connection pipe.

A wire electrode feeding apparatus or the like is provided, suitable for feeding a wire electrode along its original path without deviating from its original path. A conversion unit 9 feeds the wire electrode from a feeding inlet 21 to a feeding outlet 25 using a machining liquid. A roller 23 changes the feeding direction of the wire electrode. A discharging unit 27 discharges the machining liquid toward the feeding outlet 25 in a direction tangential to the contact face of the roller 23, to generate a flow of the machining liquid. On the other hand, a diverted flow path for the machining liquid is defined along the contact face of the roller 23 from the feeding outlet 25 side to the feeding inlet 21 side. An intake unit 29 takes in air according to the pressure of the machining liquid to supply the air to the diverted flow path.

A wire electrode feeding apparatus or the like is provided, suitable for feeding a wire electrode along its original path without deviating from its original path. A conversion unit 9 feeds the wire electrode from a feeding inlet 21 to a feeding outlet 25 using a machining liquid. A roller 23 changes the feeding direction of the wire electrode. A discharging unit 27 discharges the machining liquid toward the feeding outlet 25 in a direction tangential to the contact face of the roller 23, to generate a flow of the machining liquid. On the other hand, a diverted flow path for the machining liquid is defined along the contact face of the roller 23 from the feeding outlet 25 side to the feeding inlet 21 side. An intake unit 29 takes in air according to the pressure of the machining liquid to supply the air to the diverted flow path.

A wire electrical discharge machine having an auto wire feeding function includes: guide parts arranged on a wire feed path along which the wire electrode is fed so as to guide the feeding of the wire electrode; fluid paths formed with the guide parts to supply a compressed fluid to the wire feed path; a compressed fluid supply device to supply the compressed fluid to the fluid paths; a tension detector to detect the tension of the wire electrode; and a control device that controls the compressed fluid supply device so as to supply the compressed fluid to the fluid paths, and based on the detection result from the tension detector, determines whether or not the wire electrode has reached a supply position of one of the fluid paths on the wire feed path to which the fluid has been supplied.

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 controls a second motor unit including motors for feeding a wire electrode in a wire running direction in which the wire electrode extends, so as to feed the wire electrode at a set feed rate during a machining period from a first time point at which the wire electrode moving relative to a workpiece in a direction intersecting the wire running direction is estimated to enter the workpiece, to a second time point at which the wire electrode is estimated to exit the workpiece. The second motor unit is controlled so as to feed the wire electrode at a feed rate lower than the set feed rate during at least one of a first non-machining period from a processing start time point to the first time point and a second non-machining period from the second time point to a processing end time point.

A method for electroerosion machining includes providing an electrode assembly comprising an electrode body having a tube-shaped body that defines a hollow interior and one or more inserts affixed to the electrode body to form a cutting surface on the electrode assembly, positioning the electrode assembly adjacent a workpiece to be machined, and providing power to the electrode assembly so as to energize the electrode assembly, with the electrode assembly and the workpiece being at opposite electrical polarities. The method also includes advancing the electrode assembly through the workpiece, with a working gap being maintained between the inserts and the workpiece across which a pulse electric current is passed to remove material from the workpiece, wherein, upon advancing the electrode assembly through the workpiece, a core is formed that is completely separated from a remainder of the workpiece and is contained within the hollow interior of the electrode body.