PROCESS AND INSTALLATION FOR EXTERNAL REWORKING OF WORN COUPLINGS

摘要

The invention relates to a process and an installation for the external reworking of worn couplings used in drilling pipes, by build-up welding in active gases medium. According to the invention, the process makes the protective layer by helical building-up using alloyed electrode wire and flux core, with increased flow rate of protective gas, so that some welding seams overlap on 1/5...1/4 of their width, followed by a local tempering thermal treatment at a temperature of 500 degree C, for 30 min. The claimed installation for applying the process is provided with a transmission with belts (3) and toothed wheels (4) ensuring the main rotation motion of a drilling pipe (5) mounted on a main shaft (6), the swinging and translation motion of a welding head (13) being achieved by means of a belt transmission (10) and a lead screw (11) integral with the carriage supporting the welding head (13). The swinging motion thereof is ensured by a space cam (14) driven into the rotation motion by a toothed wheel gearing (15).