An electric discharge machining unit capable of stably supplying working fluid to the vicinity of a portion to be machined. The electric discharge machining unit includes a tool electrode, a housing, an electrode guide, and a working fluid supplying device. The housing includes a fitting hole having a tapered surface. A first supply path is formed in the housing. The electrode guide includes a tapered portion and an ejection opening formed on a lower surface. A first flow path is formed in the electrode guide. The tapered portion is configured to be fitted into the fitting hole to connect the first flow path to the first supply path. The working fluid supplied from the working fluid supplying device to the first supply path and the first flow path is ejected from the ejection opening.

Tool electrodes for and methods of electrical discharge machining are provided. In one exemplary aspect, a tool electrode for machining features into a workpiece is provided that allows for increased machining speed without sacrificing the quality of the machined features. Moreover, a tool electrode is provided that eliminates or reduces the high cost associated with customized tool electrodes. In particular, a tool electrode is provided that includes a plurality of electrode elements arranged and spaced apart in a digitized matrix representative of a tooling shape for machining features into a workpiece. The plurality of electrode elements are spaced apart from one another and arranged in the digitized matrix by digitizing an analog electrode tool configured to machine the feature into the workpiece or a volume of the feature to be machined into the workpiece.

The present invention provides a non-contact wire array tension control device for controlling a plurality of tension respectively corresponding to a plurality of electrical discharge wires, including delivering spools and electromagnets. The delivering spool has a magnetic end and a wire outputting end, the wire outputting end is coupled with an electrical discharge wire for outputting the electrical discharge wire. A plurality of electromagnets are coupled to the corresponding magnetic end for controlling a spin rate of the corresponding delivering spool, wherein the spin rate of the corresponding delivering spool is controlled by adjusting a magnetic force generated by the electromagnet. Moreover, a magnetic direction of the electromagnet is parallel to an axial direction of the delivering spool. The invention uses the electromagnets to control the magnetic damping force of the delivering spools for simultaneously controlling the tension of the electrical discharge wires by non-contact method.

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 includes: an electrode unit for supplying a machining current to an electrode gap; a switch for changing impedance between a machining power source and the electrode unit; and a controller for, at the time of a core retaining process, controlling the switch to set the impedance to be higher than the impedance in a cutting process and thereby suppressing the machining current flowing through the electrode gap.

A method of polishing a surface of an object disposed within a gas chamber is provided. The method includes filling the gas chamber with a discharging medium to a predefined pressure, applying a voltage between an electrode and the surface, calibrating a height of the electrode relative to the surface so as to establish electrical breakdown threshold criteria, and scanning the electrode with respect to the surface so as to sequentially position the electrode over a plurality of locations on the surface, each location characterized by a surface error. When a respective location in the plurality of locations has a surface error that meets the electrical breakdown threshold criteria, electrical breakdown occurs, whereby the electrical breakdown results in a discharging pulse that polishes the surface.

An EDM machine includes a machine head, a wire guide, a machining wire extending from the wire guide to the machine head, a rotary table mounted to a first surface and a fixed table mounted to the rotary table, and a fixture mounted to the fixed table. The fixture includes a mounting portion substantially circumscribing the fixture. The mounting portion further includes a mounting surface. The mounting surface is closer to a first surface than an upper surface of the fixed table.

An electric discharge machining apparatus includes a tool electrode that performs electric discharge machining to a workpiece, a tubular extended guide in which the tool electrode is inserted, a long nozzle in which the tool electrode is inserted with a tip protruded, and provided along an outer wall surface of the extended guide so as to provide mist generating space between the extended guide and the long nozzle, a compressed gas supplying device supplying compressed gas into the mist generating space, and a pressurized working fluid supplying device supplying pressurized working fluid into working fluid filling space between the tool electrode and the extended guide

An electric discharge machining apparatus includes a tool electrode that performs electric discharge machining to a workpiece, a housing in which the tool electrode is inserted, a compressed gas supplying device for supplying compressed gas into a mist generating region which is provided between an inner wall of the housing and the tool electrode, a first flow path through which the compressed gas flows and connecting the compressed gas supplying device with the mist generating region, a pressurized working fluid supplying device for supplying pressurized working fluid into the mist generating region, and a second flow path through which the pressurized working fluid flows and connecting the pressurized working fluid supplying device with the mist generating region.

A method for forming a heat exchanger plate includes providing a precursor having a body with a first face and a second face opposite the first face and at least one internal passageway; and pluralities of first and second fin precursors respectively protruding from the first and second faces. First and second fin height profiles are formed by removing material from the respective fin precursors via wire electro-discharge machining.