| 摘要 |
PURPOSE:To obtain optimum valve operating characteristics and a high output over the entire range, and improve fuel consumption, by connecting or disconnecting a rocker arm abutting against a low-speed cam and the upper end of a valve and a cam arm abutting against a high-speed cam by means of a mesh portion. CONSTITUTION:A low-speed cam 2 and a high-speed cam 3 are mounted to a cam shaft 1. A rocker arm 5 abutting against the upper end of a valve stem at one end abuts against the low-speed cam 2 at the other end, and a cam arm 8 abuts against the high-speed cam 3. Meshing dogs 10 and 11 are formed between both the arms 5 and 8, and are normally biased to a disconnected direction by a spring 12. In high-speed running, a push rod 16 is operated by an electromagnetic device 15 to push the cam arm 8 and mesh the meshing dogs 10 and 12 with each other, thereby driving a valve through the high-speed cam 3. Thus, the valve is driven with optimum operating characteristics according to engine speeds to thereby obtain a high output over the entire range and improve fuel consumption. |
