Provided is a power supply unit, which is to be used for a multi-wire electrical discharge machining apparatus arranged to slice a material to be machined by an electrical discharge generated between a wire group including a plurality of turns of a wire arranged in parallel and the material to be machined, and to which a power supply terminal to be brought into contact with the wire group at a time to supply a voltage to the wire group is mounted, the power supply unit including: a mounting portion to which the power supply terminal to be brought into contact with the wire group at a time is mounted; and an adjusting portion arranged to adjust an inclination of the mounting portion in a direction crossing a running direction of the wire group.

This narrow-hole electric discharge machine (100), which performs electric discharge machining by relatively moving a narrow-hole electrode (28) attached to a main spindle (114) and a workpiece (130) attached to a table (118), comprises: a positioning guide (16) which is attached to a guide arm (142) below the main spindle, through which the narrow-hole electrode is inserted such that a lower portion of the narrow-hole electrode is movable in the direction of an axis line (CL0), and which supports the narrow-hole electrode; and a power feeder (10) which is provided at a predetermined position directly above the positioning guide of the guide arm, comes into direct contact with the narrow-hole electrode movable in the axis line direction and feeds power to the narrow-hole electrode, wherein the distance from a power feed position to the tip of the positioning guide is constant regardless of the length of the narrow-hole electrode.

A wire electric discharge machining apparatus is constructed in such a manner as to include: a wire electrode having a plurality of cutting wire portions that are separated from one another in parallel and are opposed to a workpiece; a machining power supply that generates a pulsed machining voltage; a plurality of power feed contact units that are electrically connected to the cutting wire portions and apply the machining voltage between the cutting wire portions and the workpiece; and a nozzle that ejects machining liquid from an ejection opening toward an electrode gap along the cutting wire portions.

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.

A wire machining method includes: a wire electrode set as cutting wires provided in parallel with a distance between the cutting wires of which a predetermined regional part faces a workpiece; a machining power source that generates a pulse-shaped machining voltage; and plural feeder units that are electrically connected to the plural cutting wires respectively of the wire electrode and supply the machining voltage between the cutting wires and the workpiece respectively. In the parallel cutting wires, the feeder units are arranged such that a direction of a current passed to at least a part of the cutting wires becomes a direction different from a direction of a current passed to other cutting wires.

The invention relates to an electrode holder (1, 2, 14) for the multichannel electrical discharge machining in electrical discharge machines. It comprises a holding element (17), a central body (15) and an electrode mounting section (19). According to the invention, the electrode mounting section (19) includes at least two clamping sections (22) for clamping electrodes (9, 10), wherein each clamping section (22) is connected, preferably via a current feeder section (21), with an own current supplying circuit (20) leading from the periphery of the electrode holder (1, 2, 14) to the respective electrode clamping section (22). The current supply circuits (20) are electrically isolated from each other by one or more insulating elements (8, 12, 25, 26, 30). Preferably the current supplying circuits (20) are allocated in or at the central body (15) of the electrode holder (1, 2, 14).

A wire electric discharge machining apparatus includes a wire electrode and upper and lower guide devices guiding the wire electrode, and includes: a power conductor moving in a first direction as a horizontal axis direction and supplying power by contacting the wire electrode; and a fixing device fixing the power conductor in the lower guide device and switchable between a fixed state, in which a movement of the power conductor relative to the lower guide device in a second direction as another horizontal axis direction orthogonal to the first direction is not possible, and a non-fixed state in which such relative movement is possible. The wire electric discharge machining apparatus includes: a pressing device, movable relative to the lower guide device and pressing the power conductor in the non-fixed state to move in the second direction; and a movement device, moving the pressing device relative to the lower guide device.