A wire electrical discharge machine includes: a travelling route formed of multiple divisional regions, through which a wire electrode is fed by an auto wire feeding mechanism; and a memory storing failure evaluation reference data on the auto wire feeding for every divisional region. The wire electrical discharge machine detects failure of the auto wire feeding and locate the tip position of the wire electrode at the time of failure and causes a controller to determine whether to perform or stop retry of the auto wire feeding based on the located tip position and the failure evaluation reference data for every divisional region.

A wire-cut EDM machine in which the position of the liquid level of machining fluid is adjusted at the time of automatic wire threading includes a shape information acquisition unit for acquiring information on the shape of an object to be machined, a wire-threading position information acquisition unit for acquiring information on a wire-threading position of a wire electrode based on relative positions of upper and lower wire guides, and a liquid level position adjustment unit for acquiring the height of the object to be machined in the vicinity of the wire-threading position based on the information on the shape of the object to be machined and adjusting the position of the liquid level of the machining fluid at the time of automatic wire threading.

A wire electrical discharge machine includes a guide pipe arranged in a path along which a wire electrode is fed from a feed roller to a workpiece, and formed with an insertion hole through which the wire electrode is inserted, a compressed air supply device configured to supply compressed air to the insertion hole so that compressed air flows through the insertion hole along a feed direction of the wire electrode, a database configured to store data indicative of a relationship between rigidity information of the wire electrode and pressure information of compressed air, and a controller configured to set pressure of the compressed air supplied to the insertion hole, based on the rigidity information of the wire electrode fed to the workpiece and the data.

The present invention provides a wire electric discharge machine including an automatic connection function that enables automatic connection to be securely performed even when no person is present in the surroundings of the machine (with no manual operation). The wire electric discharge machine performs automatic setting procedure of a connection condition and determines whether it is the time point stored in a computer numerical control (CNC) device. When it is the time point stored (YES), an automatic connection condition 2 is read. When it is not the time point stored (NO), an automatic connection condition 1 is read. The wire electric discharge machine then performs disconnection procedure and connection procedure to complete the process.

An automatic wire connecting device includes a heating electrode that heats an electrode wire by applying a current to the electrode wire, a tension applying unit that applies a tension to the electrode wire to which the current is applied by the heating electrode, a tension control unit that controls the tension applied by the tension applying unit, and a power supply control unit that applies a heating current smaller than a preset annealing current to the electrode wire until a first set time elapses since the current starts to be applied and increases the current applied to the electrode wire to reach the annealing current during a second set time after the first set time elapses since the current starts to be applied.