method for cutting processing, welding and rica rica of metallic and non-metallic materials by means of electric arc and device for its implementation

摘要

1521622 Arc welding systems SECHERON SOUDYRE SA 27 Jan 1976 [27 Jan 1975] 03158/76 Heading H2H [Also in Divisions B3 and H3-H5] An arc torch has its arc subjected to a rotating magnetic field whose magnitude and speed of rotation can be controlled to vary the rotational speed and the path taken by the arc. The field is produced by a polyphase, e.g. three-phase electromagnet 10 provided with equispaced pole pieces 17, 18, 19 arranged about the arc 6. Three vertical arms 11, 12, 13 carrying windings 14, 15, 16 are interconnected at their upper ends by an annular flux return member. In the plasma torch shown gas is supplied through a hollow electrode 2 and through an aperture 9 in the torch sleeve 1. The arc 6 is struck between nozzle electrode 4 and hollow electrode 2 and is rotated by the electromagnet 10, the windings 14, 15, 16 of which are supplied from separate phases. The controlled electromagnet polyphase supply 21 comprises a frequency control unit 29, a variable frequency pilot generator 22, a polyphase current generator 23 and three amplifiers 24, 25, 26 supplying current to the windings 14, 15, 16. Amplifiers 24, 25, 26 are controlled by an amplitude adjusting unit 27 servo controlled by a pulse generator 28 itself controlled by pilot generator 22. The amplitude and speed of rotation of the magnetic field can be regulated periodically or aperiodically by varying the supply frequency, the supply voltage and the arrangement of the windings. Thus it is possible to cover an area of a workpiece delimited by the maximum and minimum trajectories of the arc. In Fig. 5 and 6 (not shown), the pole pieces of the electromagnet are arranged downstream of the nozzle of a transferred arc plasma torch and a TIG torch respectively. Likewise in Fig. 7 (not shown) a torch with a consumable wire electrode has its arc controlled by a three-phase magnet whose poles are arranged about the torch axis downstream of the torch body. Cutting, electro-erosion welding and depositing metals and non-metals may be carried out with the torches disclosed.