| 摘要 |
PURPOSE:To selectively drive both low and high speed cam chafts in a variable valve timing device, by disposing a switching clutch between the low and high speed cam shafts. CONSTITUTION:A low speed cam shaft 3a alone is driven to rotate when a clutch 8 is opened, and therefore a valve is opened and closed through a rocker arm 2. The valve lift curve thereof is as shown by, for example, a curve (a). Then, a high speed cam shaft 3b is also driven to rotate through gears 6, 6 together with the low speed cam shaft 3a, when the clutch 8 is closed, and therefore the valve is opened and closed through the rocker arm 2. The valve lift curve thereof is as shown by, for example, a curbe (b). With this arrangement, the low and high speed cam shafts 3a, 3b are selectively driven, thereby predetermined valve timing may be obtained. |
