Procédé et dispositif d'usinage par électro-érosion

摘要

In a spark or arc erosion or deposition process, or an electrolytic machining or deposition process, an electrode 3 is used having the general shape 4 of the region 2 to be treated, and which is movable transversely into positions such as 4a, 4b during the process. This enables, in the case of electro-erosion, a single electrode to be used for coarse and final shaping using sparks of differing intensity. The invention is applicable to the formation of internal or external shapes, Fig. 2 (not shown), and for completely piercing a workpiece or forming a recess therein. In an apparatus for performing the process, Fig. 4, the elctrode holder 18 is mounted for transverse adjustment within a carrier 15c by eight micrometer screws P1-P8 which permit movement in eight radial directions, Fig. 3 (not shown). The carrier is mounted on the feed head of a spark erosion machine. In another embodiment, Fig. 7, the electrode holder 32 is mounted on a carrier 31, secured to the feed head, through two shaft assemblies 38, 40 and 39, 41 respectively. These assemblies permit eccentric adjustment of the holder 32 on tis carrier by a micrometer screw 45 and are interconnected by toother gearing 38a, 42, 39a. Eccentric adjustment is set by a gauge inserted between surfaces 67a, 68a. After adjustment the shafts 38, 39 are rotated by a motor 52, Fig. 8 (not shown), which provides an orbital movement for the electrode. In a modification, Fig. 12, the elctrode holder 111 is centred within its carrier sleeve 109 by sets of springs 130, 131, Fig. 13 (not shown), but can be moved transversely along guide balls 110 by an eccentric adjusting screw 119 in a drive shaft 105, 114. The screw 119 has a differential thread 119a, 119b, Fig. 14 (not shown), to provide accurate adjustment. When shaft 105 is rotated by a motor 102, the holder 111 has an orbital movement. The feed movement may be performed simultaneously with the transverse movement, Fig. 16 (not shown), or the electrode may have a feed movement only whilst workpiece is moved transversely by one or more adjustment devices K, K1, Fig. 17 (not shown). The apparatus does not refer to the application of electrolytes.