Patent ID: 8256402
Filing Date: 2012-09-04
Classification: F01N,F02B,F02D,Y02T

Abstract:
1. An exhaust passage structure of a multi-cylinder engine which has a valve-overlapping term when an intake valve in an intake stroke and an exhaust valve in an exhaust stroke open together for a specified period of time, comprising: three or more independent passages coupled to respective cylinders which are different from each other, at least two of the independent passages being separate passages which are coupled to a single cylinder independently, and at least one of the independent passages being a common passage which is coupled to plural cylinders in common; a collective portion where said three or more independent passages collect; an exhaust turbocharger arranged downstream of said collective portion; rotary throttle valves arranged respectively in said three or more independent passages upstream of said collective portion, each of the rotary throttle valves being capable of providing a throttle portion where an opening area of the passage formed therewith is reduced in a specified engine operational state, wherein said throttle valves which are arranged in said at least two of the independent passages coupled to the single cylinder independently are supported by a common rotary axis, and the cylinders to which said independent passages equipped with said throttle valves supported by the common rotary axis are coupled have exhaust strokes which are not adjacent to each other.