| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize a variable valve gear while maintaining a valve closed condition in the minimum lift condition and improving fuel economy performance effectively. SOLUTION: When a cam shaft 13 rotates in synchronization with a crank shaft, an oscillating cam 20 oscillates through an eccentric cam 15, a link arm 25, a rocker arm 18, and a link member 26 to open, close, and operate an intake valve 12. When a control shaft 16 rotates, a turning position of the oscillating cam 20 is relatively changed through the rocker arm 18 and cam lift characteristic is changed. A predetermined valve clearance is set between the oscillating cam 20 and the intake valve 12 in a base circle sectionθ1. In the minimum lift condition in which amount of cam lift of the oscillating cam 20 becomes the minimum, the maximum amount of cam lift of the oscillating cam 20 is set to be larger than 0 and smaller than the valve clearance. COPYRIGHT: (C)2007,JPO&INPIT |
