A wire electrical discharge machine determines the position of an endface of a workpiece by relatively moving a wire electrode toward the workpiece. The wire electrical discharge machine includes: a voltage application control unit configured to continuously apply voltage pulses between the wire electrode and the workpiece; a voltage detection unit configured to detect a voltage between the wire electrode and the workpiece; a pulse occurrence ratio calculation unit configured to calculate a pulse occurrence ratio that is a ratio of the number of the voltage pulses detected by the voltage detection unit to the number of the voltage pulses applied per a predetermined time by the voltage application control unit; and an endface position determination unit configured to determine the position of the endface of the workpiece based on the pulse occurrence ratio.

A method for the monitoring of a wire electrical discharge machining (WEDM) process, the method comprising the steps of: setting a unit observation length for the signal acquisition, continuously acquiring at least one process signal which is representative of an amount of material removed by at least one discharge and the position (X;Y) of said at least one discharge, and determining, based on said at least one process signal and one or more properties of a current machining, a cumulated amount of material removed per unit observation length along a machining path, including amounts of material removed by travelling in a forward cutting direction and amounts of material removed by travelling in a reverse cutting direction.

A method for the monitoring of a wire electrical discharge machining (WEDM) process, the method comprising the steps of: setting a unit observation length for the signal acquisition, continuously acquiring at least one process signal which is representative of an amount of material removed by at least one discharge and the position (X;Y) of said at least one discharge, and determining, based on said at least one process signal and one or more properties of a current machining, a cumulated amount of material removed per unit observation length along a machining path, including amounts of material removed by travelling in a forward cutting direction and amounts of material removed by travelling in a reverse cutting direction.

A cable includes: a linear conductor; a plurality of resin hollow tubes which are disposed around the conductor so that an air layer is formed around the conductor and which extend in a longitudinal direction of the conductor; and an insulating protective member configured to protect the conductor and the plurality of hollow tubes.

A cable includes: a linear conductor; a plurality of resin hollow tubes which are disposed around the conductor so that an air layer is formed around the conductor and which extend in a longitudinal direction of the conductor; and an insulating protective member configured to protect the conductor and the plurality of hollow tubes.

A wire electrical discharge machine is configured to perform removal machining of a workpiece by applying a voltage to a machining gap between a wire electrode and the workpiece through a feeder to generate electrical discharge and is provided with a feeder deterioration detection unit configured to detect deterioration of the feeder. The feeder deterioration detection unit includes a detection unit configured to detect a machining current value during the machining and a detection unit configured to detect the number of electrical discharges during the machining.

A wire electrical discharge machine is configured to perform removal machining of a workpiece by applying a voltage to a machining gap between a wire electrode and the workpiece through a feeder to generate electrical discharge and is provided with a feeder deterioration detection unit configured to detect deterioration of the feeder. The feeder deterioration detection unit includes a detection unit configured to detect a machining current value during the machining and a detection unit configured to detect the number of electrical discharges during the machining.

A wire electrical discharge machine includes an upper wire guide and a lower wire guide supporting a wire electrode, a probe provided on an upper guide block having the upper wire guide, an offset storage unit for storing an offset amount from the upper wire guide to the probe, a position shift drive unit for changing the relative position between the table, and the upper and lower wire guides, a drive controller for controlling the position shift drive unit, a contact position calculator for calculating a contact position that is a position of the probe when it comes in contact, and a machining start position calculator for calculating a machining start position of the wire electrode, based on at least two contact positions and the offset amount. The drive controller controls the position shift drive unit so that the position of the wire electrode becomes the machining start position.

A wire electrical discharge machine includes an upper wire guide and a lower wire guide supporting a wire electrode, a probe provided on an upper guide block having the upper wire guide, an offset storage unit for storing an offset amount from the upper wire guide to the probe, a position shift drive unit for changing the relative position between the table, and the upper and lower wire guides, a drive controller for controlling the position shift drive unit, a contact position calculator for calculating a contact position that is a position of the probe when it comes in contact, and a machining start position calculator for calculating a machining start position of the wire electrode, based on at least two contact positions and the offset amount. The drive controller controls the position shift drive unit so that the position of the wire electrode becomes the machining start position.

A control device includes a speed setting unit configured to set a relative movement speed of a wire electrode with respect to a workpiece depending on the average of gap voltage per unit time, i.e., average gap voltage, and set the relative movement speed so as to move the wire electrode backward when the average gap voltage is less than a threshold, and a map compensation unit configured to change the threshold from a first threshold that is set when the amount of change in the average gap voltage is lower than a predetermined variation, to a second threshold that is greater than the first threshold, when the average gap voltage has changed in a decreasing direction and the amount of change in the average gap voltage becomes equal to or greater than the predetermined variation.