| 摘要 |
PROBLEM TO BE SOLVED: To inhibit heat gain at a time of forming a padding portion on a movable member, to inhibit occurrence of adhesive wear on a slide contact surface, and to improve wear resistance to extend service life.SOLUTION: A valve device includes a padding portion integrally provided on a slide contact surface of either a valve rod 205 serving as a movable member or a valve element 204. The padding portion is formed by generating a pulsed discharge between an electrode formed of a compact mainly containing a metal and a treatment target portion of either the valve rod 205 or the valve element 204, and welding and depositing a material of the electrode on a surface of the treatment target portion. The valve device includes a surface layer integrally provided on a slide contact surface of a bush 201 serving as a stationary member or a sleeve. The surface layer is formed by forming a first coating film by a surface hardening heat treatment by means of a metal infiltration method. The slide contact surface of either the valve rod 205 or the valve element 204 and the slide contact surface of either the bush 201 or the sleeve slidably contact each other according to a valve opening/closing operation. |
