1. Field of the Invention
The present invention relates to an intake system of an engine. More particularly, the present invention relates to an intake system of an engine that is disposed at an intake passage to form a tumbling flow of air or air-fuel mixture.
2. Description of Related Art
Generally, there is a method of forming tumble in intake air so as to enhance combustion of an engine.
A flap valve is disposed at an intake passage so as to generate tumble, and a technique of adjusting the opening rate of the flap is being applied.
Speed of intake air is increased, pressure thereof is decreased, fuel amount that is attached on a wall of an intake port is reduced, and the fuel is effectively vaporized by forming the tumble.
Accordingly, the fuel is uniformly mixed, such that a lean combustion is enabled, quality of exhaust gas is improved, the combustion is effectively performed, and the temperature of the exhaust gas purification catalyst is quickly raised. Thus, the purification efficiency of the exhaust gas purification catalyst is also improved.
In a structure having a first bank and a second bank such as a V6 engine, research has being been undertaken to efficiently control the opening rate of the flap disposed at the intake passage of respective banks, and it is necessary that the durability thereof is good, interference between components is low, structure is simple, and assembly is easy.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.