PROCESS FOR RESTORING OPERATING CONDITION OF WORN PIECES IN FUEL INJECTORS FOR DIESEL ENGINES OF ROAD MOTOR VEHICLES, BY WEAR COMPENSATION

摘要

The invention relates to a process for restoring the operating condition of worn pieces in Diesel engine fuel injectors of road motor vehicles, by which, for compensating the wear resulting from the material losses during operation, certain types of wear-resistant materials or substances are deposited in various ways, in successive compensating layers, in order to restore circularity, conicity, roughness of the surfaces of pieces operating in pairs, to bring them to the dimensions of the pieces as new, and to bring them within the tolerance margins for normal operation, control, monitoring, quality supervising, up to obtaining the optimal parameters required. According to the invention, the process consists of successive stages to be run by the pieces during the reconditioning process, comprising the following operations: cleaning, degreasing, visual examination for fault identification, size checking, removal, by grinding or honing, of the superficial layer which is impaired by the faults ascertained after the visual examination; size checking, deposition, on the active surface, of wear-resistant materials to compensate the dimensional modifications resulting after grinding and honing, respectively, the surface of the last deposited compensating layer is scoured with a diamond paste and the circularity, conicity and roughness of the surface are checked, the diameters dimensions are checked and the pieces intended to operate together are associated, i.e. the body of a nozzle (2) with a needle (3) of the nozzle (2), and a cylinder (4) with a rod (5), respectively, while observing the admitted dimensional tolerances, hydraulic check-outs, tightness check-outs and pressure discharge time check-outs are performed in apparatuses or test benches, according to the specifications set by the producers of the new pieces.