Machining support for electro-erosion machining, Method of using such a machining support

Abstract

The invention relates to a machining support (1) intended to be fixed to a table of an electro-erosion machining machine to produce a plurality of holes in a part received on the machining support by driving in a plurality of electrodes (4) in the form of rods carried by a movable head (2) of the machine parallel to a plunge direction (3) of the head, the machining support comprising a guide (5) having parallel through orifices (6) into which the electrodes penetrate to project from the guide when the head is brought closer to the machining support, as well as a pruning shears (100) removably attachable to the machining support and actuable once the electrodes are engaged in the guide to cut at least a portion of the electrodes projecting from the guide. The invention also relates to a method of using this machining support. FIGURE OF THE ABSTRACT: Fig. 2

Description

Title of the invention: Machining support for electro-erosion machining, Method of using such a machining support

[0001] The invention relates to drilling holes in a part by the sinking electroerosion process.

[0002] BACKGROUND OF THE INVENTION

[0003] Some parts require the production of a series of parallel holes. For example, a distributor blade of a turbine of a jet engine or a turboprop generally has a series of ventilation holes along the entire length of the blade (typically several dozen holes) which are generally produced by electroerosion by driving a series of parallel electrodes (for example in the form of copper rods) into the blade.

[0004] Patent application FR 3 125 451 of the present applicant thus proposes a device for guiding an electrode of an electroerosion drilling device.

[0005] Usually, the part to be drilled is received on a machining support fixed to a table of the machine, while the electrodes are mounted on a head movable in a plunging direction, generally vertical, the electrodes all extending in the plunging direction.

[0006] After fixing the part to be drilled on the machining support, the part is immersed in a bath of dielectric liquid, while the movable head is lowered so as to gradually penetrate the end of the live electrodes into the part, to the desired depth. Then the movable head is raised to release the electrodes from the part and thus allow its extraction from the machining support.

[0007] However, the electrodes wear out regularly, and it is necessary to remove the burnt ends. It is of course possible to remove all the electrodes, cut them and replace them on the head, but this operation is time-consuming. It is also possible to cut each electrode directly on the moving head using hand shears, but this operation is imprecise and tedious for the operator.

[0008] SUBJECT OF THE INVENTION

[0009] The object of the invention is to propose a device for cutting to length all the electrodes in place on the moving head, precisely and quickly. Summary of the invention

[0010] With a view to achieving this aim, a machining support is proposed intended to be fixed to a table of an electro-erosion machining machine for producing a plurality of holes in a part, received on the machining support, by driving a plurality of rod-shaped electrodes carried by a movable head of the machine parallel to a plunge direction of the head. The machining support comprises: - a guide having parallel through holes into which the electrodes penetrate to protrude from the guide when the movable head is brought closer to the support; - a secateur which can be removably attached to the machining support and which can be operated once the electrodes are engaged in the guide to cut at least part of the electrodes protruding from the guide.

[0011] Thus, when after several machining operations, the burnt ends of the electrodes must be removed, it is sufficient, before machining a new part, to return the pruning shears to the guide of the machining support, to move the movable head towards the machining support to make the electrodes penetrate into the guide until they protrude from it, then to operate the pruning shears to cut the electrodes and thus remove the burnt ends. Then the movable head is moved away from the machining support to make the electrodes come out of the guide, and the pruning shears are withdrawn. Machining of the parts can then resume with electrodes cut cleanly and to length. The operation of cutting the electrodes takes only a few moments.

[0012] According to a particular arrangement, the pruning shears comprise a frame fitted to a contour of the guide.

[0013] Preferably then, the frame carries stretchers having proximal ends on which is articulated an operating handle so that, when the secateurs are actuated, a blade is brought closer to an anvil in a cutting direction perpendicular to the plunge direction.

[0014] More preferably, the blade is carried by a blade holder pushed by the operating handle.

[0015] According to a particular arrangement, the blade holder is slidably guided on the frame, the guidance preferably being achieved using pins carried by the frame and engaged in adjusted orifices in the blade holder.

[0016] According to a particular arrangement, the anvil has orifices for receiving the electrodes so that they extend into a corner opening of the anvil into which the blade penetrates.

[0017] According to another particular arrangement, each stretcher comprises an oblong opening into which extends a pin carried by the frame, so that the stretchers are floating on the frame in a cutting direction.

[0018] Optionally, the pruning shears can be removably attached to the machining support and can be actuated once the electrodes are engaged in the guide to cut at once at least part of the electrodes projecting from the guide or to cut at once all the electrodes projecting from the guide.

[0019] Preferably, the stretchers have distal ends shaped like a stopper on which the anvil presses.

[0020] The invention also relates to a method of using a machining support according to the invention, comprising the steps of: - return the pruning shears to the machining support; - bring the moving head closer so that the electrodes penetrate into the guide of the machining support and protrude from it; - operate the pruning shears to cut at least part of the electrodes; - move the moving head away from the machining support to release the electrodes from the guide; - remove the pruning shears from the machining support. Brief description of the drawings

[0021] The invention will be better understood in light of the following description of a particular embodiment with reference to the figures of the appended drawings, among which:

[0022] [Fig-1] [Fig.l] is a perspective view of a machining support according to the invention, without the workpiece, and while the pruning shears have not been returned;

[0023] [Fig.2] [Fig.2] is a perspective view of the machining support of [Fig.l], the pruning shears having been attached and the movable head brought closer to the machining support to engage the electrodes in the guide and the pruning shears;

[0024] [Fig.3] [Fig.3] is a schematic sectional view at the level of the guide with the pruning shears in place, the electrodes having been engaged in the guide to be cut;

[0025] [Fig.4] [Fig.4] is an exploded perspective view of the pruning shears shown in Figures 2 and 3, the frame of the pruning shears having been shown in transparency for greater clarity. DETAILED DESCRIPTION OF THE INVENTION

[0026] The invention applies to an electro-erosion machining machine comprising a machining support 1 intended to be fixed to a table of the machine to receive a part to be drilled, and a head 2 movable relative to the machining support 1 in a plunge direction 3. The movable head 2 carries a plurality of electrodes 4, here copper rods which all extend parallel to the plunge direction 3. Here, the electrodes 4 extend in the same plane P parallel to the plunge direction 3. The distal ends of the electrodes 4 are here aligned along an oblique line 7.

[0027] The electrodes 4 are used to drill a plurality of holes in a part attached to the machining support. For this purpose, once the part is placed on the machining support, a tank of dielectric liquid is raised to immerse the part in a fluid. Then the movable head 2 is brought closer to the part to drive the distal ends of the electrodes 4 into the workpiece to the desired depth. This is well known and is only mentioned for context.

[0028] However, the distal ends of the electrodes 4 burn under the effect of electro-erosion and must be regularly cut to give the electrodes 4 healthy ends. To do this, the machining support 1 is equipped with a guide 5 extending projecting from the machining support 1. The guide 5 is pierced with a plurality of through orifices 6 extending parallel to the plunge direction 3, each facing one of the electrodes 4 so that by bringing the movable head 2 closer to the machining support 1, the electrodes 4 penetrate into the orifices 6 of the guide 5 until they project from a distal face 8 of said guide 5.

[0029] According to the invention, and as illustrated in [Fig. 3], a pruning shears 100 is attached to the machining support 1, which will enable all the electrodes 4 to be cut in a single movement. The pruning shears comprise a frame 101 which is attached to the contours of the guide 5. Of course, the pruning shears 100 have been attached to the machining support 1 before the electrodes 4 penetrate into the guide 5, as illustrated here.

[0030] The pruning shears 100 are now described in detail with reference to figures 3 and 4. As illustrated in [Fig.3], it can be seen that the frame 101 of the pruning shears 100 covers the adjustment guide 5 to precisely position the pruning shears 100 on the machining support 1. The frame 101 comprises two lateral legs 102 carrying two pins 103 which extend into oblong openings 104 formed in two stretchers 105 which are thus carried by the frame 101 while being free to float in a cutting direction 106 perpendicular to the plunge direction 3.

[0031] The stretchers 105 carry an anvil 107 having orifices 108 (only one is referenced in [Fig. 4] for clarity) to receive the electrodes 4 projecting from the distal face 8 of the guide 5 so that they extend through a wedge opening 109 formed in the anvil 107. The stretchers 105 also receive a blade holder 110 slidably mounted on the frame 101 in the cutting direction 106 on pins 111 carried by the frame 101 and engaged in adjusted orifices 112 of the blade holder 110. The blade holder 110 receives a blade 113 which extends opposite the wedge opening 109. The stretchers 105 have a distal end shaped like a striker 114 to form a support for the anvil 107 and a proximal end carrying pivots 115 on which an operating handle 116 is articulated along an articulation axis perpendicular to the cutting direction 106.To operate the pruning shears 100, it is then sufficient to push on the operating handle 116 according to the arrow 117 visible in [Fig. 3] to pivot it. The operating handle 116 has a cam profile 118 which pushes the blade holder 110 towards the anvil 107 in the cutting direction 106. The blade 113 penetrates into the wedge opening 109 of the anvil 107 until all the electrodes 4 are cut at once to eliminate their ends. burned. The cut is made along the plane of the blade 113, which is here parallel to the distal face 8 of the guide 5, which allows perfect alignment of the ends of the electrodes 4 along the oblique line 7.

[0032] The fact that the stretchers 105 are floating in the cutting direction 106 avoids imposing on the electrodes a shear between the guide 5 and the anvil 107. The latter is immobilized by the electrodes, the stretchers 105 adjusting by bearing on the anvil 107 to bring the blade 113 closer to the anvil 107 without moving the anvil 107.

[0033] This provides a precise and rapid cut of all the electrodes 4 in a single cutting operation. This cut can be easily carried out by the operator between two machining operations. Once the cut has been carried out, it is then sufficient to move the movable head 2 away to release the electrodes 4 from the pruning shears 100 and the guide 5 and remove the pruning shears 100 from the machining support 1 to continue the machining operations.

[0034] The invention is not limited to what has just been described, but on the contrary encompasses any variant falling within the scope defined by the claims.

[0035] In particular, although here a secateurs with a blade and anvil approaching parallel to themselves in a cutting direction have been illustrated, it will be possible to provide a secateurs with a blade and anvil approaching in a pivoting movement, or even to provide a secateurs with straight blades.

[0036] Although it has been indicated that the electrodes all extend along a plane P, the electrodes may extend along any surface regulated by a directrix parallel to the plunge direction. In this case, it will be sufficient to adapt the profile of the anvil and the blade to cut along this regulated surface.

[0037] Although here all the electrodes are cut at once, only a part of the electrodes can be cut (in a single stroke or in several strokes). It is also possible to have all the electrodes cut in several strokes.

Claims

Claims

1. Machining support (1) arranged to receive a workpiece to be machined and intended to be fixed to a table of an electroerosion machining machine to make a plurality of holes in the workpiece, received on the machining support, by driving in a plurality of electrodes (4) in the form of rods carried by a movable head (2) of the machine parallel to a plunge direction (3) of the head, the machining support comprising: - a guide (5) having parallel through orifices (6) into which the electrodes penetrate to project from the guide when the head is brought closer to the machining support; - a pruning shears (100) removably attachable to the machining support and actuable once the electrodes are engaged in the guide to cut at least a portion of the electrodes projecting from the guide.

2. Machining support according to claim 1, in which the pruning shears (100) comprise a frame (101) attached to a contour of the guide (5).

3. Machining support according to claim 2, in which the frame (101) carries stretchers (105) having proximal ends on which is articulated an operating handle (116) so that, when the secateurs are actuated, a blade (113) and an anvil (107) are brought together in a cutting direction (106) perpendicular to the plunge direction (3).

4. Machining support according to claim 3, in which the blade (113) is carried by a blade holder (110) pushed by the operating handle (116).

5. Machining support according to claim 4, in which the blade holder (110) is slidably guided on the frame (101).

6. Machining support according to claim 5, in which the guidance is carried out using pins (111) carried by the frame (101) and engaged in adjusted orifices (112) of the blade holder (110)

7. A machining stand according to claim 3, wherein the anvil (107) has holes (108) for receiving the electrodes (4) so ​​that they extend into a wedge opening (109) of the anvil into which the blade penetrates.

8. Machining support according to claim 3, in which each stretcher (105) has an oblong opening (104) in which extends a pin (103) carried by the frame (101), so that the stretchers are floating in the cutting direction.

9. Machining support according to claim 3, in which the stretchers (105) have distal ends shaped like a stopper on which the anvil (107) comes to bear.

10. Method of using a machining support according to claim 1, comprising the steps of: - Bringing the pruning shears (100) onto the machining support (1); - Bringing the movable head (2) closer so as to cause the electrodes (4) to penetrate into the guide (5) of the machining support to protrude from the latter; - Actuating the pruning shears to cut at least part of the electrodes; - Moving the movable head away from the machining support to release the electrodes from the guide; - Removing the pruning shears from the machining support.

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