US 4,441,004 AGranted

Multiple pipe element electrode assembly EDM method and apparatus

AssigneeInoue-Japax Research Incorporated

InventorKiyoshi Inoue

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Abstract

A multiplicity of conductive pipe elements are arranged in parallel with one another in mutually insulating relationship and are secured together in a cup to form a multiple electrode assembly. The assembly is advanced into a workpiece in the machining feed direction and additionally is displaced relative to the workpiece by a Z-axis motor in a plane orthogonal to the machining feed direction by X-axis and Y-axis motors a distance slightly in excess of the uniform spacing (Gx,Gy) between the pipe electrodes along each of two mutually orthogonal axes in the plane. The additional displacement may be effected alternatively by vibrating the pipe elements transversely to the axes thereof with an amplitude essentially equal to the said distance. For further machining of the same workpiece, a proportion of the pipe elements may be released from the securely held state and individually advanced and/or retracted with rates of movement determining the shapes of the final machined contour. The power supply comprises an AC-DC-HF-DC Pulse inverter having multiple output terminals respectively connected to the multiple pipe elements. Machining liquid is pumped to and from the machining gaps via the pipe elements.

Claims30

Dependent claims

An EDM method of machining a contoured cavity in a conductive workpiece, comprising:

(a) forming a multiple pipe assembled EDM electrode by (a1) arranging a multiplicity of conductive open-ended pipe elements two-dimensionally in parallel with one another and spaced apart from one another with a predetermined uniform minimum spacing to establish a mutually electrically insulating relationship in such a manner that an imaginary envelope surface which is substantially defined collectively by the frontal open-end portions of said conductive pipe elements has a preselected three-dimensional contour complementary with a contour of a said cavity to be machined in the workpiece and (a2) securely holding together said multiplicity of pipe elements so arranged in sub-step (a1);
(b) juxtaposing said multiple pipe assembled EDM electrode with the workpiece to define an EDM gap between the annular machining surface provided on each of said frontal open-end portions and said workpiece;
(c) flushing said multiple EDM gap with a dielectric liquid by establishing a forced flow of said dielectric liquid through said pipe elements;
(d) effecting a succession of electrical discharges through said flushed dielectric liquid across each of said multiple EDM gaps between said annular machining surfaces and the localized areas of the workpiece respective juxtaposed therewith by passing a succession of electrical pulses individually between each of said multiple pipe elements and said workpiece to cause EDM material removal from said localized areas;
and
(e) advancing said assembled electrode unitarily and relatively into said workpiece in a machining feed direction parallel with said pipe elements to a predetermined depth while relatively displacing said EDM electrode and said workpiece in a plane essentially orthogonal to said machining feed direction by a distance in excess of said predetermined uniform spacing along each of two mutually orthogonal axes on said plane.

3 more elements

An EDM apparatus for machining a cavity in a workpiece, comprising:

a multiple pipe assembled EDM electrode comprising a multiplicity of conductive open-ended pipe elements arranged two-dimensionally in parallel with one another and spaced apart from one another with a predetermined uniform minimum small spacing to establish a mutually electrically insulating relationship and further such that an imaginary envelope surface essentially defined collectively by the frontal open-end portions of said conductive pipe elements has a preselected three-dimensional contour complementary with a contour of a said cavity to be formed in the workpiece;
means for securely holding together said conductive pipe elements so arranged and supporting said multiple pipe assembled EDM electrode to define an EDM gap between the annular machining surface provided on each of said frontal open-end portions and said workpiece;
liquid supply means for establishing a forced flow of a dielectric liquid through each of said pipe elements, thereby flushing said multiple EDM gaps with said dielectric liquid;
EDM power supply means for passing a succession of EDM pulses individually between each of said conductive pipe elements and said workpiece to effect a succession of electrical discharges through said flushed dielectric liquid across each of said multiple EDM gaps between said annular machining surfaces and the localized areas of the workpiece respectively juxtaposed therewith, thereby causing EDM material removal from said localized areas;
first drive means for advancing said electrode unitarily and relatively into said workpiece in a machining feed direction parallel with said pipe elements to a predetermined depth;
and
second drive means for relatively displacing said EDM electrode and said workpiece in a plane essentially orthogonal to said machining feed direction by a distance in excess of said predetermined uniform spacing along each of two mutually orthogonal axes on said plane.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/271,982Filed 9 Jun 1981
Priority: JP 55-7838312 Jun 1980
Granted: 3 Apr 1984
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

B23H 7/28
Apparatus for moving or positioning electrode relatively to workpiece; Mounting of electrode: moving electrode in a plane normal to the feed…
B23H 1/00
Electrical discharge machining, i.e. removing metal with a series of rapidly recurring
B23H 7/22
Processes or apparatus applicable to both electrical discharge machining and electrochemical machining: electrodes specially adapted therefor or…
B23H 7/38
Processes or apparatus applicable to both electrical discharge machining and electrochemical machining: influencing metal working by using…