Patent 7302929 was granted and assigned to Keihin Corporation on December, 2007 by the United States Patent and Trademark Office.
To improve an air bypass device in bypass air flow and designing freedom, a locking stepped part 3, a bush inserting hole 4, and a valve body drive mechanism inserting hole 5 are provided above an upper end 2a of a valve body guiding hole 2 of an air control valve main body 1, an air flow-in hole 6 is provided below a lower end 2b of the valve body guiding hole 2, and an inner peripheral wall 2c of the valve body guiding hole 2 includes a plurality of air control grooves 7a . . . extending downwardly from the locking stepped part 3 and being closed by an annular bush 11 on the locking stepped part 3 to form independent air distribution chambers 12a . . . , which are connected to intake passages 8b1 . . . at the downstream side from the respective throttle valves of multiple throttle bodies T1 . . . through bypass air passages 15a . . . .