A high-speed reciprocating wire cutting process in which a wire electrode is transported and precisely guided across a machining area by means of a wire traveling circuit, whereas the cutting process is conducted by repeatedly: running the wire electrode in a first direction until a first reciprocation position, stopping and inverting the traveling direction of the wire electrode, running the wire electrode in a second direction until a second reciprocation position, stopping and inverting the traveling direction of the wire electrode.

A cutting process interruption sequence is carried out if a cutting process monitoring reveals that the cutting process must be interrupted, whereas the cutting process interruption sequence includes to continue the cutting process until the first or the second wire electrode reciprocation position, and to pause or to stop said cutting process at the wire reciprocation position.

A multi-wire electric discharge machine includes: a plurality of cutting wire sections arranged in parallel in such a way as to face a workpiece, a wire electrode being wound around guide rollers to form the cutting wire sections; a drive unit that adjusts relative distances between the workpiece and the cutting wire sections; a machining power supply that applies pulse voltages between the workpiece and the cutting wire sections; a machining-state detection device that detects machining states in the cutting wire sections; and a machining control device that controls the drive unit and the machining power supply, in which when values indicating the machining states exceed a threshold value, the machining control device outputs, to the machining power supply, commands to apply the pulse voltages according to a machining condition for avoiding breakage of the wire electrode.

A multi-wire electric discharge machine includes: a plurality of cutting wire sections arranged in parallel in such a way as to face a workpiece, a wire electrode being wound around guide rollers to form the cutting wire sections; a drive unit that adjusts relative distances between the workpiece and the cutting wire sections; a machining power supply that applies pulse voltages between the workpiece and the cutting wire sections; a machining-state detection device that detects machining states in the cutting wire sections; and a machining control device that controls the drive unit and the machining power supply, in which when values indicating the machining states exceed a threshold value, the machining control device outputs, to the machining power supply, commands to apply the pulse voltages according to a machining condition for avoiding breakage of the wire electrode.

A method for controlling a wire electrical discharge machining (WEDM) process, in which the wire traveling speed V.sub.W is adapted in-process, while cutting. The method includes, determining the size of the crater occurring at each said determined position of each discharge along the engagement line of a wire and a work piece, and the current wire traveling speed; and continuously comparing the wire wearing model with one or more wire wearing limits, and adjusting the wire traveling speed according to the comparison of the actual wire wearing model and the one or more wire wearing limits. The wire electrical discharge machining process is conducted with reduced wire consumption, safely, efficiently and profitably.

A sealing device and a wire electrical discharge machine that may reduce sludge deposition, include a seal base, a seal plate, a bellows member, a flow passage, and a guide rail member. The guide rail member is open on the inward direction side thereof to cause sludge generated by machining of an object to be machined to flow into a machining tank along with a machining liquid supplied between the bellows member and the seal plate.

A tension information acquisition device acquires tension of a wire electrode and is provided with: a back tension adjustment unit that makes the magnitude of back tension of the wire electrode zero; and an acquisition unit that acquires tension information indicating the tension on the basis of a disturbance estimate value or output torque of a feed motor when the magnitude of the back tension is zero.

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.

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 multi-wire electric discharge machine includes: a plurality of cutting wire sections arranged in parallel in such a way as to face a workpiece, a wire electrode being wound around guide rollers to form the cutting wire sections; a drive unit that adjusts relative distances between the workpiece and the cutting wire sections; a machining power supply that applies pulse voltages between the workpiece and the cutting wire sections; a machining-state detection device that detects machining states in the cutting wire sections; and a machining control device that controls the drive unit and the machining power supply, in which when values indicating the machining states exceed a threshold value, the machining control device outputs, to the machining power supply, commands to apply the pulse voltages according to a machining condition for avoiding breakage of the wire electrode.

A multi-wire electric discharge machine includes: a plurality of cutting wire sections arranged in parallel in such a way as to face a workpiece, a wire electrode being wound around guide rollers to form the cutting wire sections; a drive unit that adjusts relative distances between the workpiece and the cutting wire sections; a machining power supply that applies pulse voltages between the workpiece and the cutting wire sections; a machining-state detection device that detects machining states in the cutting wire sections; and a machining control device that controls the drive unit and the machining power supply, in which when values indicating the machining states exceed a threshold value, the machining control device outputs, to the machining power supply, commands to apply the pulse voltages according to a machining condition for avoiding breakage of the wire electrode.