Machine and method for spark erosion machining of a gerotor pump

Patent metadata

Field	Value
Publication number	US-10882128-B2
Application number	US-201815906459-A
Country	US
Kind code	B2
Filing date	Feb 27, 2018
Priority date	Mar 2, 2017
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

A spark erosion machine includes a frame with a space for spark erosion of a workpiece, a wire for cutting by spark erosion, and a wire guide head for guiding the wire across the workpiece, so as to detach an offcut from it; an offcut support mounted movably relative to the guide head, the support being configured to move at least between a retention position under the spark erosion space, where it can collect the offcut, and a retracted position; and an offcut extractor.

First claim

We claim:

1. A spark erosion machine, comprising:
a frame with a spark erosion space for the spark erosion of a workpiece;
a wire for spark erosion cutting;
a guide for guiding the wire through the workpiece to cut an offcut from the workpiece; and
a support for the offcut from the workpiece, mounted movably relative to the guide, the support being structurally and functionally configured to move at least between a retracted position, and a retention position under the spark erosion space in order to collect the offcut, the support comprising:
a notch which is configured so that, in the retracted position, the wire is outside said notch, and in the retention position the wire is engaged in said notch, wherein the notch has an enlargement in which the wire is engaged in the retention position.

2. The spark erosion machine according to claim 1 , wherein the support is movable in a plane perpendicular to the wire, the support being configured to move between a position where it intersects the wire and a position at a distance from the wire, said positions corresponding to the retention position and the retracted position, respectively.

3. The spark erosion machine according to claim 1 , wherein the support has two parallel branches forming a fork for supporting the offcut.

4. The spark erosion machine according to claim 1 , wherein the support comprises:
a horizontal upper surface for receiving the offcut.

5. The spark erosion machine according to claim 1 , further comprising:
an offcut extractor capable of entering the offcut through the spark erosion space.

6. The spark erosion machine according to claim 5 , wherein the extractor comprises:
an expandable portion formed by two levers movable relative to one another in order to lock the offcut.

7. The spark erosion machine according to claim 1 , further comprising:
a device for fixing workpieces, said device being fixed relative to the frame.

8. The spark erosion machine according to claim 1 , wherein the support is movable relative to the frame, and the guide is movable relative to the frame of the machine.

9. A spark erosion machine, comprising:
a frame with a spark erosion space for the spark erosion of a workpiece;
a wire for spark erosion cutting;
a guide for guiding the wire through the workpiece to cut an offcut therefrom;
a support for the offcut, the support being movably mounted relative to the guide, the support being configured to move at least between a retracted position, and a retaining position under the spark erosion space in order to collect the offcut; and
an offcut extractor with an expandable portion structurally and functionally adapted for entering the offcut and to extract the offcut from the workpiece.

10. The spark erosion machine according to claim 9 , wherein the expandable portion is formed by two levers that can move relative to one another within the offcut in order to lock the offcut.

11. The spark erosion machine according to claim 9 , wherein the support comprises:
a notch which is configured so that, in the retracted position, the wire is outside said notch and, in the retention position, the wire is engaged in said notch, the notch including an enlargement in which the wire is engaged in the retention position.

12. The spark erosion machine according to claim 11 , wherein the expandable portion is structurally and functionally adapted for entering in at least one of the notch and the enlargement.

13. A spark erosion machining method in a spark erosion machine having a frame with a spark erosion space for the spark erosion of an initial workpiece, a wire for spark erosion cutting of the initial workpiece, a guide for guiding the wire through the initial workpiece to cut an offcut from it, and a movable support with a notch, the spark erosion machining method comprising:
fixing the initial workpiece in the spark erosion machine;
machining the initial workpiece by means of the wire so as to detach an offcut therefrom; and
moving the movable support under the offcut so as to stop the gravitational descent of the offcut when it is detached from the initial workpiece by the wire when said wire is in the notch.

14. The spark erosion machining method according to claim 13 , wherein the offcut includes an aperture and the spark erosion machine includes an extractor, the method further comprising:
an introduction step in which the extractor enters the aperture so as to retain the offcut without the movable support.

15. The spark erosion machining method according to claim 14 , wherein the aperture extends through the offcut, and in the introduction step the extractor passes through the offcut.

16. The spark erosion machining method according to claim 14 , further comprising:
an extraction step of the offcut by lifting the offcut by means of the extractor.

17. The spark erosion machining method according to claim 13 , wherein, at the end of the machining step, the initial workpiece forms a closed loop around the offcut, and around the wire.

18. The spark erosion machining method according to claim 13 , wherein the initial workpiece is a first initial workpiece, and during the fixing step additional initial workpieces are fixed in the machining machine, so as to form a stack of initial workpieces above including the first initial workpiece, and in the machining step the wire simultaneously machines the stack so as to form a stack of identical offcuts therein.

19. The spark erosion machining method according to claim 13 , wherein at the end of the machining step, an inner pump toothed ring or an outer pump toothed ring is formed.

Assignees

• Safran Aero Boosters Sa

Inventors

• Flore David
• Peiffer Philippe
• Van Den Abeele Olivier

Classifications

• B23H11/003 Primary

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

• B23H9/003

  Making screw-threads or gears · CPC title

• F04C2230/102

  by spark erosion methods · CPC title

• F04C2/084

  Toothed wheels · CPC title

• F04C2/10

  of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member · CPC title