| 摘要 |
<p>PURPOSE:To change the opening term of an intake valve by providing a first cam shaft for driving one intake valve, and a second cam shaft for driving two intake valves, and providing a phase changing means onto one side cam shaft, in a device provided with three intake valves per one cylinder. CONSTITUTION:Three intake ports 11 to 13 and two exhaust ports 14, 15 are formed on a cylinder head 2, and the intake ports 11 to 13 are opened/closed by intake valves 21 to 23. In this state, three lines l1 to l3 are assumed in parallel with a crank shaft, and a central intake valve 21 is arranged on the line l1, and also two side intake valves 22, 23 are arranged on the line l2. Moreover, a first to a third cam shafts 31 to 33 are arranged on a cylinder head 2 opposing to respective lines l1 to l3, and the central intake valve 21 is opened/closed by the first cam shaft 31, on the other hand, side intake valves 22, 23 are opened/closed by the second cam shaft 32. Subsequently a phase changing mechanism (not shown in figure) for changing the opening/closing timing in response to the rotating position of the crank shaft, is provided in relation to the second cam shaft 32.</p> |
