| 摘要 |
PROBLEM TO BE SOLVED: To reduce sliding friction of parts which constitute a valve opening and closing mechanism. SOLUTION: A valve opening and closing mechanism for an internal combustion engine operates a valve 9 for opening and closing air supply and exhaust ports 25 and 26 by using an electromagnetic actuator 4, which is constituted by an armature 3, disposed in a gap S between a pair of electromagnets 6 and 7 and a first stem 15 for transmitting a shift of the armature 3 to the outside. In the valve opening and closing mechanism, a retainer 13 and a first return spring 2 are attached to the valve 9, a second step 14 is provided on a surface of the armature 3, that is opposite from a surface on which the first stem 15 is provided, a retainer 13' and a second return spring 1 are attached thereon, and a sliding film is provided on the surface or an end face of the stem 16 of the valve 9, end faces of the second return spring 1 or the first return spring 2, a spring bearing end face of the retainer 13 or 13', a surface or an end face of the first stem 15, a surface or an end face of the second stem 14, or one or more surfaces of the armature 3.
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