A wire electrical discharge machine to cut a workpiece by generating an electrical discharge in a dielectric working fluid between wire electrodes arranged in parallel and the workpiece includes: a work tank that stores the dielectric working fluid; a Z-axis stage that is disposed in a lower portion of the work tank and moves the workpiece in a Z-axis direction that is a vertical direction; a pillar that extends upward from the Z-axis stage and has an upper end portion located above the highest level of a fluid level of the dielectric working fluid in the work tank; an adjuster that is installed downward from a portion of the pillar located above the highest level of the fluid level, is disposed above the highest level of the fluid level, and adjusts the position or posture of the workpiece in a direction other than the vertical direction.

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 for machining a workpiece by generating electric discharge at a discharge gap between the workpiece and a wire electrode includes: a machining current setting unit for setting the magnitude of a normal machining current depending on the discharge gap state at application of a discharge induction voltage at the previous time or previous times; and a machining current control unit configured to control a main discharge circuit so as to supply the normal machining current to the discharge gap when the present discharge gap state is the normal state, control the main discharge circuit so as to supply a short-circuit machining current smaller than a predetermined current to the gap when the discharge gap state is the short-circuited state, and control the main discharge circuit so as not to supply any machining current to the gap when the discharge gap state is the open state.

A wire electrical discharge machine for machining a workpiece by generating electric discharge at a discharge gap between the workpiece and a wire electrode includes: a machining current setting unit for setting the magnitude of a normal machining current depending on the discharge gap state at application of a discharge induction voltage at the previous time or previous times; and a machining current control unit configured to control a main discharge circuit so as to supply the normal machining current to the discharge gap when the present discharge gap state is the normal state, control the main discharge circuit so as to supply a short-circuit machining current smaller than a predetermined current to the gap when the discharge gap state is the short-circuited state, and control the main discharge circuit so as not to supply any machining current to the gap when the discharge gap state is the open state.

The disclosure provides a wire electric discharge machine which has a simple configuration and can make a wire electrode fed to a machining position rotate around an axis. The wire electric discharge machine for machining a workpiece includes an upper wire guide and a lower wire guide, which stretch a wire electrode therebetween, and a rotator. A position of the rotator is changed, whereby the wire electrode is rotated around an axis.

The disclosure provides a wire electric discharge machine which has a simple configuration and can make a wire electrode fed to a machining position rotate around an axis. The wire electric discharge machine for machining a workpiece includes an upper wire guide and a lower wire guide, which stretch a wire electrode therebetween, and a rotator. A position of the rotator is changed, whereby the wire electrode is rotated around an axis.

A vibration assisted wire machining device is provided, the vibration assisted wire machining device allows a metal wire to be driven by a bi-axial sinusoidal vibration source during a wire machining process, wherein the bi-axial sinusoidal waveforms have the same amplitude, and preferably, the bi-axial sinusoidal waveforms are synchronous and always have a vibration phase difference of 90 degrees. Therefore, the present invention can reduce wire breakage risks and improve wire-cutting efficiency, and raise machining stability and material removal rate of a wire-electrical discharge machining (Wire-EDM) process performed on a workpiece, as well as achieve desirable precision of a geometric shape. It also relates to a vibration assisted wire machining device that enables metal wires associated with the abrasive slurry formed of hard abrasive grains, for performing bi-axial vibration assisted abrasive cutting or abrasive grinding on the workpiece.

In a wire electrical discharge machining device, a wire electrode released from a wire bobbin can be supplied toward a wire electrical discharge machining portion without generating permanently bending or twisting. A first pulley, which receives a wire electrode fed out from a wire bobbin and delivers the wire electrode to the downstream side, is disposed to wind the wire electrode WE to a first delivery position of an outer peripheral portion opposite to a first reception position across a central portion in a radial direction and deliver the wire electrode WE downward. The first pulley is swingable in the horizontal direction with one end in the radial direction as a fulcrum. The swing fulcrum is disposed, in the width direction of the wire bobbin, within a range from one end to the other end in the width direction of the wire bobbin.

In a wire electrical discharge machining device, a wire electrode released from a wire bobbin can be supplied toward a wire electrical discharge machining portion without generating permanently bending or twisting. A first pulley, which receives a wire electrode fed out from a wire bobbin and delivers the wire electrode to the downstream side, is disposed to wind the wire electrode WE to a first delivery position of an outer peripheral portion opposite to a first reception position across a central portion in a radial direction and deliver the wire electrode WE downward. The first pulley is swingable in the horizontal direction with one end in the radial direction as a fulcrum. The swing fulcrum is disposed, in the width direction of the wire bobbin, within a range from one end to the other end in the width direction of the wire bobbin.

A wire electrical discharge machine includes a first voltage applying circuit, a second voltage applying circuit, and a switch controller. The first voltage applying circuit includes a first DC power source for applying a positive polarity voltage across an electrode gap, and a first switch for on/off-switching of application of the positive polarity voltage. The second voltage applying circuit includes a second DC power source for applying a reverse polarity voltage to the electrode gap, and a second switch for on/off-switching of application of the reverse polarity voltage. The switch controller controls the first switch and the second switch so that the first switch and the second switch are not turned on simultaneously. The first DC power source and the second DC power source are set up so that the absolute value of the reverse polarity voltage is lower than the absolute value of the positive polarity voltage.