An electric discharge machine and an electric discharge machining method for the electric discharge machine are provided. The electric discharge machine includes a circulation pump for pressure-feeding a work fluid in a dirty fluid tank to a filter; a jetting pump for pressure-feeding the work fluid in the clean fluid tank to a jetting nozzle; a feeding pump for pressure-feeding the work fluid in the clean fluid tank to the work tank; and a pump controller for inverter-controlling the circulation pump, the jetting pump, and the feeding pump. The pump controller includes a jetting pump controller configured to set an inverter frequency of the jetting pump, and a feeding pump controller configured to acquire the flow rate of the inverter-controlled jetting pump and set an inverter frequency of the feeding pump based on the flow rate of the inverter-controlled jetting pump.

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 draining mechanism according to an embodiment comprises a block in which a through hole is formed therethrough along a direction intersecting the gravity direction. The through hole is provided with a first guide portion and a second guide portion. The block comprises: a gas channel connected to the through hole between the first guide portion and the second guide portion; and a discharge port connected to the through hole between the first guide portion and the second guide portion, extending along the gravity direction, and connected to the outside of the block.

A wire electrical discharge machine includes: a mounting table having a placement plane on which a workpiece can be placed; a first guide portion and a second guide portion for stretching a wire electrode therebetween. The first guide portion is integrally equipped with a probe. The relative position in the placement plane between the probe detecting its abutment with the workpiece and the first guide portion before moving the relative position between the first guide portion and the second guide portion is stored as an offset. This offset is corrected based on the tilt information indicating the tilt state of the workpiece relative to the placement plane. Thus, it is possible to obtain the corrected offset in accordance with the tilt state of the workpiece after changing the relative position between the first guide portion and the second guide portion.

A guide pipe provided along a movement path of a wire electrode between a direction change pulley and a winding device and guiding the wire electrode has antistatic properties. A gas-liquid mixed fluid is supplied into the guide pipe. A suction nozzle passes between a pair of rollers of the winding device and is directly or indirectly connected to an outlet side of the guide pipe. The suction nozzle suctions the gas-liquid mixed fluid in the guide pipe and a tip of the wire electrode by a suction device and captures the wire electrode. The captured wire electrode is wound by the winding device.

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 storage device for a wire electrical discharge machine is provided with a used wire electrode storage box configured to recover a used wire electrode and a dielectric fluid suction unit into which a fluid is poured to produce a negative pressure based on a Venturi effect so that a dielectric fluid accumulated in the storage box can be drawn in through an outlet of the storage box.

A control unit controls a holding device so that a cutting feed stage is driven when cutting is started to move upward a workpiece fixing plate on which a workpiece is placed and fixed and a pair of machining fluid flow straightening plates relative to a pair of machining fluid escape prevention plates so as to bring the workpiece fixing plate and the pair of machining fluid flow straightening plates closer to a plurality of cutting wire portions, and a workpiece retainer is held in an initial cutting position until the workpiece reaches a first position by the upward movement, and controls the holding device to release the hold of the workpiece retainer after the workpiece reaches the first position.

A wire electrical discharge machine includes a contact detector provided at a lower nozzle and configured to detect contact of a wire electrode with the exterior of the lower nozzle, a suction unit configured to suction working fluid into the lower nozzle, and a wire feeding mechanism configured to pass the wire electrode through a machining hole in a workpiece and feed the wire electrode toward the lower nozzle. When auto wire feeding is performed with a work-pan containing working fluid, the wire electrode (is fed toward the lower nozzle by the wire feeding mechanism while the suction unit suctions the working fluid into the lower nozzle. When the contact detector detects contact of the wire electrode with the exterior of the lower nozzle, the wire electrode is rewound by the wire feeding mechanism.

A wire electric discharge machine is provided with a storage unit configured to store the flow rate of a machining fluid delivered to a sealing portion in a machining tank in association with the flow rate of the machining fluid delivered to a nozzle. The flow rate of the machining fluid delivered to the nozzle is measured, and the flow rate of the machining fluid to be supplied to the sealing portion is read from the flow rate storage unit and set, based on the measured flow rate.