Variable-throat exhaust turbocharger and method for manufacturing constituent members of variable throat mechanism

摘要

A variable-throat exhaust turbocharger can be provided, in which is used a means to reduce wear of the contact surfaces of the connection pin parts (10) which are formed integral with the lever plates (1) or the drive ring (3) and the grooves (3y) into which the connection pin parts (10) are engaged, and which has a means to prevent slipping out of the drive ring (3) from the nozzle mount (5) toward the lever plate (1) to prevent probable occurrence of fail in action of the variable nozzle mechanism (100) caused by the slipping out of the drive ring (3) is provided by the invention. In the invention, the connection pin parts (10) to make connection between the lever plates (1) and drive ring (3) of the variable throat mechanism are formed integral with either the lever plates (1) or the drive ring (3) by extrusion or by precision casting, and at least the connection pin parts (10) or grooves (3y) into each of which each of the connection pin parts (10) is engaged are treated with surface hardening including diffusion coating.