METHOD TO RESTORE WORN OUT PISTON HOLE FOR PISTON PIN AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2015 - IPC B23P6/00 B21D31/00 

FIELD: machine building.

SUBSTANCE: identification of piston defects is carried out and its worn out hole is machined by a reamer fixed in a machine chuck. Prior to machining the piston is installed in a mandrel rigidly fixed at the machine support and the piston hole for piston pin is axially centred by the reamer axis with the reamer being prevented from rotation, due to floating longitudinal movement of the piston along the mandrel walls and rotation of the piston around its longitudinal axis. The device comprises a reamer mounted at a lathe machine and consisting of lead-in, cutting and exit parts, by one end it is fixed in the machine chuck and the other end is pressed by the machine back centre. The mandrel for the piston consisting of a hollow cylinder is rigidly mounted on the machine support, two through holes for the reamer are made opposite each other on the side surface of the mandrel, the vertical axes of the cylinder and the reamer are perpendicular to each other.

EFFECT: invention allows for accurate machining of the surface of the holes for a piston pin, reduced consumption of spare parts and materials for engine repair, service life of pistons increased by at least 80% of new parts service life.

2 cl, 1 dwg