PURPOSE: To plan elongation of life of a seal-ring by anodizing fitting surfaces of a piston and a valve in a housing made of aluminum or the like and improving an anti-friction property while coating with fluoric resin and improving a lubricity.
CONSTITUTION: A housing 10, made of aluminum or alumimum alloys, is constituted with first and second members 11, 12, and a valve fitting surface 13 is formed on one side of an aperture provided on the first housing member 11 so ss to intersect with a predetermined angle. A rack shaft 18 provided with rack-teeth 17 is slidably penetrated through housing 10, while a pinion shaft 23 flexible connected to a steering shaft 21 is supported with a bearing within the housing 10 in an axial line, intersecting the axial line of the rack shaft 18 with a predetermined angle. In this case, a fitting surface (internal surface of the second member 12) of a piston and the valve fitting surface 13 in the housing 10 are anodized and the surfaces thereof are coated with fluoric resin.
SAKURAI HIROSHI
YAMAMOTO MASAJI
