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.

Provided is an electric discharge machining apparatus including: a wire guide, positioning and guiding a wire electrode stretched perpendicularly to a horizontal line; a power conductor, energizing the wire electrode; a guide assembly, accommodating the wire guide and the power conductor; an extrusion member, provided in the guide assembly and pushing out the power conductor in a direction of the wire electrode; a drive device, reciprocating the extrusion member in a horizontal uniaxial direction; a fixing device, fixing the power conductor in a predetermined position within the guide assembly by the extrusion member; and an elastic member, provided coaxially with the extrusion member of the fixing device and constantly pushing out the power conductor in the direction of the wire electrode in a state in which the power conductor is attachable to and detachable from the guide assembly.

An apparatus includes one wire electrode wound multiple times around a plurality of guide rollers to form a parallel wire part in which a plurality of wire cutting parts are arranged in parallel, a discharge waveform control device that controls an interpolar voltage waveform based on a discharge waveform command, and a wire running control device that controls running of the wire electrode based on a wire electrode running command. Further, there is a cutting stage drive device that controls a relative position between the parallel wire part and the workpiece based on a stage command, a machining state acquisition section that acquires a cutting part electrical characteristic or electrode state information as machining state information, and a machining control device that determines the wire electrode running command, the discharge waveform command, and the stage command based on the machining state information.

An upper guide assembly includes an upper wire guide, an upper power feed contact, and a power feed contact movement device, and a lower guide assembly includes a lower power feed contact. The upper power feed contact and the lower power feed contact are configured to contact the wire electrode to supply power by moving in a horizontal direction from initial positions not contacting the wire electrode. The power feed contact movement device is configured to move the upper power feed contact in the horizontal direction from the initial position by a predetermined offset amount. The offset amount is set based on a machining condition including at least one of a condition of the wire electrode, a condition of a workpiece, and a surface roughness required for a cut surface of the workpiece.

The present invention is directed to a current feeding device for the supply of electrical current to a wire electrode traveling in an electro-erosion machine during the machining operation. The current feeding device comprising: a rotary electrically conductive body which is in contact with the wire electrode; at least one bearing for supporting the rotary electrically conductive body at one side; and a brush for electrically contacting the rotary electrically conductive body and for supporting the rotary electrically conductive body at the other side of the body and opposite side to the bearing. The brush is at the rotary axis of the rotary electrically conductive body.

The present invention is directed to a current feeding device for the supply of electrical current to a wire electrode traveling in an electro-erosion machine during the machining operation. The current feeding device comprising: a rotary electrically conductive body which is in contact with the wire electrode; at least one bearing for supporting the rotary electrically conductive body at one side; and a brush for electrically contacting the rotary electrically conductive body and for supporting the rotary electrically conductive body at the other side of the body and opposite side to the bearing. The brush is at the rotary axis of the rotary electrically conductive body.

A contact tip (1) for gas metal-arc welding comprising: A body (3) of a metal material with a tubular base portion (4) and two or more fingers (5a, 5b) extending in the axial direction from a front end of the base portion; At least one wire-feed conduit (7) extending axially through the body, in which a welding wire is to be received and fed; slots (10a, 10b) arranged between the fingers in order to space these apart, and A spring means (11) surrounding the fingers and exerting a radially acting spring force on the fingers of such strength that the fingers, when cool, are kept spaced apart, such that no pressure will be exerted on the casing surface of a welding wire introduced in the wire-feed conduit, and when heated to a temperature above the softening temperature of the metal material, are compressed by the spring force radially inward in order to exert pressure on the casing surface of a welding wire received in the wire-feed conduit.

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.

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.

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.