Electric discharge machining die sinking device

Patent metadata

Field	Value
Publication number	US-8963041-B2
Application number	US-201213426113-A
Country	US
Kind code	B2
Filing date	Mar 21, 2012
Priority date	May 28, 2009
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

An electric discharge machine die sinking device includes a tank for holding a fluid, and at least one electrode in the tank having a shape for imparting to a first portion of a workpiece. A workpiece holder positions the workpiece at least partially immersed in the fluid and alternately moves the workpiece between an inoperable position and a first operable position of the first electrode at which electric discharge machining occurs on the first portion. A pulse generator creates an electric discharge between the first portion and the first electrode to remove material from the first portion in response to the workpiece being in the first operable position. Movement of the workpiece from the electrode flushes particle containing fluid away from the workpiece and the electrode. A segmented electrode includes a separate pulse generator for each segment may also be employed.

First claim

What is claimed is:

1. An electric discharge machining (EDM) die sinking device comprising:
a tank for holding a fluid;
a plurality of electrode segments fixed in the tank, the plurality of electrode segments immersed in the fluid,
wherein each of the plurality of electrode segments are electrically insulated from adjacent electrode segments in the plurality of electrode segments;
a workpiece holder for positioning the workpiece at least partially immersed in the fluid and alternately moving the workpiece between an inoperable position and a first operable position of the plurality of electrode segments at which electric discharge machining occurs on the first portion; and
a plurality of pulse generators for creating an electric discharge between the first portion and each of the plurality of electrode segments to remove material from the first portion in response to the workpiece being in the first operable position,
wherein each of the plurality of pulse generators are coupled to one of the plurality of electrode segments.

2. The EDM die sinking device of claim 1 , wherein the plurality of pulse generators cause the plurality of electrode segments to have a positive polarity and the workpiece to have a negative polarity.

3. The EDM die sinking device of claim 1 , further comprising a plurality of pulse controllers, each of the plurality of pulse controllers coupled to each of the plurality of electric pulse generators for generating an electric discharge from each electrode segment independently of other electrode segments in the plurality of electrode segments.

4. The EDM die sinking device of claim 1 , wherein the plurality of electrode segments are spaced apart from one another.

5. The EDM die sinking device of claim 1 , wherein the electric discharge machining creates a particle containing fluid including particles of the workpiece suspended therein, and movement of the workpiece between the inoperable position and the first operable position causes the particle containing fluid to be at least partially drawn out of a space vacated by the workpiece.

6. The EDM die sinking device of claim 5 , further comprising a nozzle for injecting fluid into the space vacated by the workpiece.

7. The EDM die sinking device of claim 1 , further comprising a workpiece holder controller for controlling movement of the workpiece holder.

8. The EDM die sinking device of claim 7 , wherein the workpiece holder controller detects a voltage between the workpiece and each electrode segment of the plurality of electrode segments, and controls a feeding speed of the workpiece towards the plurality of electrode segments based on the voltages.

9. The EDM die sinking device of claim 8 , wherein the workpiece holder controller:
increases the feeding speed in response to none of the plurality of electrode segments discharging to the workpiece, and
decreases the feeding speed or distances the workpiece from the first electrode in response to one of the plurality of electrode segments discharging to the workpiece at a voltage lower than a threshold.

10. The EDM die sinking device of claim 8 , wherein the workpiece holder controller maintains the feeding speed of the workpiece toward the plurality of electrode segments in response to all of the plurality of electrode segments discharging to the workpiece at a substantially identical voltage.

11. An electric discharge machining (EDM) die sinking device comprising:
a first electrode including a plurality of electrode segments, the first electrode including a first shape for imparting to a first portion of a workpiece;
a second electrode including a plurality of electrode segments, the second electrode including a second shape for imparting to a second portion of the workpiece;
a separate electric pulse generator coupled to each electrode segment of the first electrode and to each electrode segment of the second electrode;
a pulse controller coupled to each separate electric pulse generator for generating an electric discharge on each electrode segment independently of other electrode segments to remove material from the first portion and the second portion of the workpiece;
a workpiece holder for positioning of the workpiece relative to the first electrode and the second electrode, and a workpiece holder controller for controlling movement of the workpiece holder, wherein the workpiece holder controller detects a voltage between the workpiece and each electrode segment of the first electrode, and controls a feeding speed of the workpiece towards the first electrode based on the voltage, and:
increases the feeding speed in response to none of the plurality of electrode segments discharging to the workpiece,
decreases the feeding speed or distances the workpiece from the first electrode in response to one of the plurality of electrode segments of the first electrode discharging to the workpiece at a voltage lower than a threshold, and
maintains the feeding speed of the workpiece toward the first electrode in response to one of the plurality of electrode segments of the first electrode discharging to the workpiece at an expected discharge voltage level or all of the plurality of electrode segments of the first electrode discharging to the workpiece at the expected discharge voltage level.

12. The EDM die sinking device of claim 11 , further comprising:
a tank for holding a fluid, the first electrode and the second electrode being positioned in the tank, and
wherein the workpiece holder positions the workpiece at least partially immersed in the fluid between the first electrode and the second electrode,
wherein the workpiece holder moves the workpiece between an inoperable position, a first operable position of the first electrode at which electric discharge machining occurs on the first portion of the workpiece and a second operable position of the second electrode at which electric discharge machining occurs on the second portion of the workpiece.

Assignees

• Luo Yuefeng
• Gen Electric

Inventors

• Luo Yuefeng

Classifications

• B23H9/10

  Working turbine blades or nozzles · CPC title

• B23H11/003

  Mounting of workpieces, e.g. working-tables · CPC title

• B23H7/26 Primary

  Apparatus for moving or positioning electrode relatively to workpiece; Mounting of electrode · CPC title

• B23H1/00

  Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric · CPC title