Abstract: The power supply device for electrical discharge machining includes circuit component elements for converting a voltage from a power supply to a given pulse voltage which can be supplied to a minute gap between an electrode and a workpiece so that electrical discharge can be generated in the minute gap; a substrate on which the circuit component elements are mounted; a highly thermally conductive metal piece member disposed opposed to the substrate and including a cavity portion therein, the cavity portion being fittable with the circuit component elements or being capable of holding the circuit component therein; and, cooling appratus for cooling heat generated by the circuit component elements and conducted to the metal piece member by use of a machining liquid supplied to the minute gap as a cooling medium.

Abstract: A wire electrical feeding device for an electrical discharge machine. Vibrator assemblies are utilized to feed the wire electrode through electrode guides of the electrical discharge machine. A first vibrator assembly vibrates through a locus which includes a component in the wire feeding direction. The wire electrode is selectively pressed against the first vibrator assembly when the first vibrator assembly is moving in a direction having a component in a wire feeding direction. In the alternative, a second vibrator assembly, which is coupled to the first, clamps the wire electrode when the first vibrator assembly is moving in a direction having a component in the wire feeding direction. The vibrator assembles may each be driven at different vibrational frequencies.

Abstract: A wire electrical discharge machining apparatus comprising a nozzle for a machining liquid for jetting the machining liquid from a jet hole, a surrounding member for intercepting the flow of the machining liquid jetted from the nozzle so as to prevent the machining liquid from flowing out to a portion other than the spark gap, and a holding device for holding the surrounding member so as to removably mount the surrounding member on the nozzle and so that the surrounding member does not slip off while mounted. The holding device facilitates both the operation of mounting and dismounting the surrounding member on and from the nozzle and replacement of the surrounding member. Since the surrounding member does not slip off while it is mounted, smooth preparation and working is enabled.

Abstract: A machining-liquid injection nozzle unit for use in a traveling-wire EDM apparatus comprises a pair of nozzles disposed opposite to each other through a workpiece and serving to inject a machining liquid individually toward the workpiece while permitting insertion of a wire electrode therethrough in the axial direction thereof coincident with injection of the machining liquid, and a liquid screening member so shaped as to surround the axis of the wire electrode and attached to at least one of the nozzles. The liquid screening member has a low friction coefficient to the workpiece and serves to diminish the lateral force exerted on the fore end of the upper or lower nozzle due to its sliding motion, hence preventing deterioration of the machining precision. The nozzle unit further includes a piston connected to the liquid screening member and capable of producing a predetermined pressure toward the workpiece by the machining liquid in the nozzle.

Abstract: A wire electrode for wire cut electric discharge machining having a core wire of high thermal conductivity (made of copper, silver, aluminum or their alloys), an intermediate layer formed by a low-boiling point material (zinc), and an outermost layer of brass having high mechanical strength.

Abstract: A wire electrode for use in wire-cut electrical discharge machining which can be used under a high machining tension and which produces no appreciable deposit on the workpiece it is used to machine. The wire of the invention may be made of an amorphous metal or amorphous alloy composed primarily of iron, cobalt, or copper, and coated on its surface with a layer of a metal such as zinc, magnesium, tin, lead, cadmium or alloys thereof. Alternatively, the wire electrode may be a wire of highly fine crystalline particles fabricated by super-quenching from a pure metal or an alloy of a pure metal in a molten state at a cooling rate of 10.sup.3 to 10.sup.5 .degree.C./sec in a super-quenching process such as a spinning process which forms a wire in a rotating liquid layer.

Abstract: A wire electrode for wire-cut electrical discharge machining includes a wire composed of a core made of one of an amorphous pure metal and an amorphous alloy and a thin crystalline layer serving as a surface of the core. The wire may be coated on its surface with a layer of a material of high electrical conductivity. The amorphous alloy may be Cu-based, Fe-based, or Co-based. The use of an amorphous pure metal or alloy yields a wire electrode of much greater tensile strength than previous wire electrodes, enabling a higher machining speed.

Abstract: The gap width g between a workpiece 12 and the outlet of a nozzle 7, 8 is automatically and continuously controlled in accordance with a predetermined configuration of a groove 15 being machined to facilitate the exhaust of injected machining liquid 10 and entrained dust particles 14 from the groove.