Selectively hardening internal surface of cylinders

摘要

Method consists of guiding a laser beam into the cylinder and deflecting the beam onto the side wall to bring about the heat treatment, and constantly measuring the temp. of the exposed area and adjusting the parameters of the laser beam in response to the temp. in order to control the heat treatment. The temp. measuring is carried out by reflecting infrared rays from the edges of the treated area to an infrared probe via a mirror and optical fibres. The laser beam is deflected onto the cylinder by deflector which is cooled by coolant running through conduits. The glass fibres run in a tube which is cleaned and cooled by air drawn through the tube. The support part has a tube element through which the beam runs and an outer tube (15) which rotatably supports the inner tubes enabling its movement in an axial direction.