Piezoelectric Injector for Direct Fuel Injection

1 . A method for producing a nozzle body, the method comprising:

preparing a nozzle-body blank which has a central axis and in a first and a second axial end;

proceeding from the first axial end, incorporating a blank cavity into the nozzle-body blank, producing a blank wall between the blank cavity and an external region of the nozzle-body blank;

adapting, by means of an electro-chemical processing procedure which comprises electro-chemical subtraction, at least part of a contour of the blank wall, thereby producing a wall of a cavity of the nozzle body.

2 . The method as claimed in claim 1 , wherein the electro-chemical processing procedure comprises:

providing an electrolyte and a cathode;

inserting the cathode into the blank cavity;

placing the electrolyte into at least one part-region of the remaining vacant volume of the blank cavity; and

applying a predefined voltage profile between the cathode and the nozzle-body blank.

3 . The method as claimed in claim 2 , wherein the predefined voltage profile comprises a pulsed voltage profile.

4 . The method as claimed in claim 1 , wherein during the electro-chemical processing procedure part of the contour of the blank wall is adapted to produce a blind hole.

5 . The method as claimed in claim 1 , wherein during the electro-chemical processing procedure part of the contour of the blank wall is adapted to produce a seat region for a nozzle needle.

6 . The method as claimed in claim 1 , wherein during the electro-chemical processing procedure part of the contour of the blank wall is adapted to produce a guide region for guiding a nozzle needle.

7 . The method as claimed in claim 2 , wherein the cathode includes a non-conducting component supporting the cathode on the nozzle-body blank during the electro-chemical processing procedure.

8 . The method as claimed in claim 7 , wherein the cathode has a cathode cavity extending along the central axis; and

during the electro-chemical processing procedure the electrolyte is placed through the cathode cavity into at least a part-region of the remaining vacant volume of the blank cavity.

9 . The method as claimed in claim 2 , further comprising rotating or oscillating the cathode during the electro-chemical processing procedure.

10 . The method as claimed claim 1 , wherein prior to the electro-chemical processing procedure:

preparing a nozzle-body blank includes tempering the blank, and

at least part of the contour of the blank wall is abraded by means of an abrasive process within the blank cavity.

11 . The method as claimed in claim 10 , wherein:

the cathode includes a non-conducting component supporting the cathode on the nozzle-body blank during the electro-chemical processing procedure;

the cathode is disposed in an axially extending component cavity of the non-conducting component so as to be axially movable in relation to the central axis; and

the non-conducting component has a seat;

during an abrasive process part of the contour of the blank wall is adapted to form a seat region for a nozzle needle is configured; and

during the electro-chemical processing procedure the seat of the non-conducting component is brought to bear on the seat region, and the cathode is guided within the component cavity of the non-conducting component such that part of the contour of the blank wall is adapted to form a blind hole.

11 . The method as claimed in claim 4 , further comprising forming at least one injection bore which penetrates the blank wall of the nozzle-body blank from the blank cavity into the external region of the nozzle-body blank in the region of the blind hole and/or of the seat region prior to the electro-chemical processing procedure.

12 . A device for processing a workpiece, the device comprising:

an electrode with a central axis; and

a non-conducting component with an axially extending component cavity;

wherein the electrode is disposed at least partially within the component cavity and axially movable therein; and

the electrode is guided within the component cavity during a processing procedure.

13 . The device as claimed in claim 12 , wherein the non-conducting component includes a seat; and

the workpiece to be processed rests on the seat during processing procedure.

15 . The device as claimed in claim 12 , wherein the non-conducting component includes a stop for the electrode.