A wire electrical discharge machine which performs electrical discharge machining on a workpiece, includes: a worktable on which the workpiece is placed; a placement area detector that divides the top surface of the worktable into multiple areas and detects the areas where the workpiece is placed; a placement time measuring unit that measures placement time for which the workpiece is placed on each of the areas detected by the placement area detector; and a cumulative time storage that adds up the placement times measured by the placement time measuring unit for each of the areas as a cumulative time for the area.

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.

An electric discharge machine is provided. The electric discharge machine includes: an axis drive part moving a tool electrode in at least one axial direction; and a sensor unit detecting a linear movement position of the axis drive part in the axial direction. The sensor unit includes a measurement scale having a linear shape, a position detector scanning the measurement scale and obtaining position information, and a pair of adjustment blocks fixed to both ends of the measurement scale or the position detector and erected perpendicular to an extension direction of the measurement scale. The adjustment blocks are fixed to the axis drive part and are curved in the axial direction due to a temperature change.

A method of manufacturing a jointed device of a medical instrument includes providing a machining fixture on a wire electrical discharge machine having an electrical discharge wire. The fixture includes member holes each adapted to accommodate at least one workpiece, the workpiece being adapted to form a portion of the jointed device of the medical instrument. At least two workpieces each include a first workpiece and a second workpiece, accommodated within at least two member holes of the member holes. The fixture is associated with the wire electrical discharge machine so that the electrical discharge wire can cut at most one workpiece at a time. The machining fixture is rotated around a fixture rotation axis at a predetermined angle, which is chosen to provide that the electrical discharge wire can cut only one workpiece at a time. The workpieces are cut by the electrical discharge wire.

A method of manufacturing a jointed device of a medical instrument includes providing a machining fixture on a wire electrical discharge machine having an electrical discharge wire. The fixture includes member holes each adapted to accommodate at least one workpiece, the workpiece being adapted to form a portion of the jointed device of the medical instrument. At least two workpieces each include a first workpiece and a second workpiece, accommodated within at least two member holes of the member holes. The fixture is associated with the wire electrical discharge machine so that the electrical discharge wire can cut at most one workpiece at a time. The machining fixture is rotated around a fixture rotation axis at a predetermined angle, which is chosen to provide that the electrical discharge wire can cut only one workpiece at a time. The workpieces are cut by the electrical discharge wire.

A method for controlling a wire electrical discharge machining process, wherein the method comprises the following steps: dividing a workpiece height H.sub.WP into a number N.sub.S of vertical sections S of the workpiece, setting a defined observation period T.sub.M, N.sub.DTM, with each discharge Di, determining a discharge position of each discharge, counting the number of discharges determining any numbers of discharges and adjusting at least one process parameter.

A method for controlling a wire electrical discharge machining process, wherein the method comprises the following steps: dividing a workpiece height H.sub.WP into a number N.sub.S of vertical sections S of the workpiece, setting a defined observation period T.sub.M, N.sub.DTM, with each discharge Di, determining a discharge position of each discharge, counting the number of discharges determining any numbers of discharges and adjusting at least one process parameter.

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.

High-speed wire electrochemical-discharge cutting method (HS-WECDM), in which a work piece is processed by means of a wire electrode, in which consecutive negative polarity pulses are applied at said wire electrode, thereby at least partially developing discrete electrical discharges, wherein the method further includes, applying positive polarity pulses at the wire electrode between the negative pulses, and that an ignition occurring with each positive polarity pulse is immediately detected, and that the positive polarity pulses are immediately interrupted.