Sealing structure of a rotary valve in an internal combustion engine

In a sealing structure of a rotary valve in an internal combustion engine in which a recess is formed adjacent an opening portion of a rotary valve proper at an opening portion of a combustion chamber defined in a housing;

• an annular seal member slidably fitted in said recess is resiliently pushed against an opposing part of said rotary valve proper by means of a resilient means;
• said resilient means comprises an annular spring interposed between a lower surface of said seal member and an opposite bottom surface of said recess such that said annular spring is in contact at one point with said lower surface of said seal member and at another point with said bottom surface of said recess;
• and an inward space at the side of a combustion chamber opening and an outward space at the side of an inner wall of said recess being separated from each other by said annular spring, which is formed of one complete piece;
• the improvement wherein:
• said annular spring has substantially a laid-down V-shaped cross-section opened to high pressure gas at the inner diameter side thereof;
• said spring having upper and lower ends at only the inner diameter side of said spring which are respectively in free contact with said lower surface of said seal member and said opposite bottom surface of said recess;
• and
• said upper and lower ends of said laid-down V-shape of the cross-section of said annular spring are directed and extend respectively upwardly and downwardly therefrom, said upper and lower ends having end surfaces which are in free contact with said lower surface of said seal member and said opposite bottom surface of said recess, respectively, such that leakage of high pressure gas from inside said annular spring is prevented at said free contact end surface of said ends of said annular spring.