Valve operating system for internal combustion engines.

摘要

A valve operating system for internal combustion engines comprises a free cam follower (9) which is disposed between first and second drive cam followers (7,8) operatively connected to engine valves and which is capable of becoming free relative to the engine valves, first and second guide holes (31, 37) respectively provided in the first and second drive cam followers (7,8) with their axes corresponding to each other. The guide holes (31, 37) are opened to the free cam follower (9). A double open-ended guide hole (36) is provided in the freee cam follower (9) in correspondence to the axes of the first and second guide holes (31, 37). A first change-over pin (27) is axially slidably received in the first guide hole (31) and adapted to be fitted into the guide hole (36), and a second change-over pin (28) is axially slidably received in said guide hole (36) with one end thereof abutting against the first change-over pin (27), and is adapted to be fitted into said second guide hole (37). A restricting pin (29) is axially slidably received in said second guide hole (37) while being spring-biased toward said second change-over pin (28), with one end thereof abutting against the other end of said second change-over pin. This construction ensures that fitting of the first change-over pin into the guide hole as well as fitting of the second change-over pin into the second guide hole can be reliably performed.