| 摘要 |
PROBLEM TO BE SOLVED: To prevent scuffing at the time of high speed medium load low inertia and high speed low load high inertia by making this synchronizer ring of Fe system sintered alloy and applying nitriding in addition to blast treatment and steam treatment at least on its inner peripheral surface. SOLUTION: An Fe system alloy sintered body is manufactured by blending and mixing specified quantity of graphite powder in iron powder or low alloy steel powder and sintering it at 1,000-1,200 deg.C after making it into a green compact in a metal mold. Thereafter, surface roughness is made 30-70μmRz by applying blast treatment on an inner peripheral surface of a synchronizer ring made of the sintered body worked in a specified shape, an iron oxide film is formed by steam treatment, formation of nitride in the inside of sintered alloy is prevented by sealing holes of the sintered alloy, and impact resistance is maintained. Furthermore, a nitrided layer is formed by nitriding treatment, and its hardness is made Hv 400-700. Consequently, an oil film formed on a contact surface with an objective member on the inner peripheral surface becomes thinner, a boundary lubricating state is maintained, and scuffing can be prevented even at the time of sliding of high speed medium load low inertia and high speed low load high inertia.
|
