A primary power supply charges a capacitor by turning on a switching element and, upon completion of charging, turns off the switching element. Then, an AC pulse voltage is applied to the gap between a wire electrode and a workpiece by alternately turning on and off a switching element present in a secondary power supply. After a dielectric breakdown occurs between the wire electrode and the workpiece, the switching element is turned on to connect the capacitor so that the capacitor supplies a pulse current for machining.

A dielectric working fluid centralized management system is equipped with a dielectric working fluid adjustment apparatus for adjusting the fluid quality of a dielectric working fluid of a plurality of wire electrical discharge machines, a dielectric working fluid delivery and reception control member for controlling delivery and reception of the dielectric working fluid between a plurality of dielectric working fluid storage tanks disposed corresponding respectively to the plurality of wire electrical discharge machines, and in which the dielectric working fluid is stored, and the dielectric working fluid adjustment apparatus, and a dielectric working fluid quality controller, which receives dielectric working fluid information from the plurality of wire electrical discharge machines and controls the dielectric working fluid delivery and reception control member, or both the dielectric working fluid delivery and reception control member and the dielectric working fluid adjustment apparatus.

An electrical discharge machining apparatus includes: a surface plate; a machining tank that surrounds the surface plate, retains a machining liquid, and has at least a part that serves as a substantially box-shaped vertically moveable ascent/descent machining tank, the ascent/descent machining tank having an outlet in an ascent/descent inner wall of the ascent/descent machining tank; an ascent/descent device that raises and lowers the ascent/descent machining tank; a sub-tank that receives the machining liquid that overflows from the machining tank; a slit that is provided in an end wall of the sub-tank for allowing a connection member to pass through, the connection member connecting the ascent/descent machining tank and the ascent/descent device; and a seal that is arranged in a gap between the ascent/descent machining tank and an inner wall of the sub-tank and prevents the machining liquid in the machining tank from leaking out into the sub-tank.

An electrical discharge machining apparatus includes: a surface plate; a machining tank that surrounds the surface plate, retains a machining liquid, and has at least a part that serves as a substantially box-shaped vertically moveable ascent/descent machining tank, the ascent/descent machining tank having an outlet in an ascent/descent inner wall of the ascent/descent machining tank; an ascent/descent device that raises and lowers the ascent/descent machining tank; a sub-tank that receives the machining liquid that overflows from the machining tank; a slit that is provided in an end wall of the sub-tank for allowing a connection member to pass through, the connection member connecting the ascent/descent machining tank and the ascent/descent device; and a seal that is arranged in a gap between the ascent/descent machining tank and an inner wall of the sub-tank and prevents the machining liquid in the machining tank from leaking out into the sub-tank.

In a method of welding a cut-out part with a workpiece at a preselected area in a thickness direction of the workpiece in a wire electrical discharge machining to retain temporarily or tentatively the part on the workpiece, a wire electrode 5 tilted in posture cuts the workpiece 6 to form a slant cutting surface 30 at a spark discharge location in a desired contour 21 in the workpiece 6. The wire electrode 5 after kept in an upright posture executes the welding process on the workpiece 6 along the slant cutting surface. A plurality of the welded spots is formed over a preselected length at preselected areas in the thickness direction of the workpiece 6. Even if the cut-out part 26 weighs more or the spark discharge is executed on the workpiece 6 overlapped one on the other, the welding spot 20 is formed in the thickness direction of the workpiece 6 adequately depending on the working situation to tentatively retain the cut-out part 26 on the workpiece 6.

In a method of welding a cut-out part with a workpiece at a preselected area in a thickness direction of the workpiece in a wire electrical discharge machining to retain temporarily or tentatively the part on the workpiece, a wire electrode 5 tilted in posture cuts the workpiece 6 to form a slant cutting surface 30 at a spark discharge location in a desired contour 21 in the workpiece 6. The wire electrode 5 after kept in an upright posture executes the welding process on the workpiece 6 along the slant cutting surface. A plurality of the welded spots is formed over a preselected length at preselected areas in the thickness direction of the workpiece 6. Even if the cut-out part 26 weighs more or the spark discharge is executed on the workpiece 6 overlapped one on the other, the welding spot 20 is formed in the thickness direction of the workpiece 6 adequately depending on the working situation to tentatively retain the cut-out part 26 on the workpiece 6.

An object of the present invention is to accurately position a wire electrode and a work. A control device included in a wire electric discharge machine of the present invention causes, in a state in which movement of the wire electrode in a longitudinal direction is stopped, a capacitance measuring section to measure capacitance while causing a driving section to relatively move a wire electrode and a work, thereafter causes, in a state in which the control device causes a wire moving section to move the wire electrode in the longitudinal direction, the capacitance measuring section to measure the capacitance, and causes the driving section to adjust relative positions of the wire electrode and the work.

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.

A machine learning apparatus includes: a state observation unit that observes a characteristic shape, an adopted plan, and a determination result as state variables, the characteristic shape representing a shape of a part of a product of wire electric discharge machining, adjustment of machining conditions being deemed as necessary for the part of the product, the adopted plan being an adjustment method selected from among one or more adjustment methods for adjusting the machining conditions to improve machining performance for the part indicated by the characteristic shape, the determination result indicating whether implementation of the adopted plan is effective in improving machining performance for the part corresponding to the characteristic shape; and a learning unit that learns the machining condition adjustment method according to a data set created based on the state variables.

Methods of repairing a part having a firtree-shaped feature requiring rework are disclosed. An embodiment of the method includes receiving the part having the firtree-shaped feature requiring rework. The part is installed in a machine configured for wire electrical discharge machining (EDM). A location of the firtree-shaped feature relative to a datum of the machine is then determined. Wire EDM is performed on the firtree-shaped feature.