EXHAUST GAS RECIRCULATION DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent the contraflow of recirculation gas to a throttle valve through an intake pipe and adhesion thereof as deposite in an exhaust gas recirculation device. SOLUTION: In the case of a butterfly throttle valve 3, an opening 15 is usually formed vertically across a rotary shaft under a slightly opened state. In the state of drawing, however, a recession 52 formed of a part of a spherical surface is formed by a pipe wall of an intake pipe 5 by means of a thick portion 53. The opening 15 is formed only on a lower portion of the throttle valve 3 while the upper portion of the throttle valve 3 is opposed to the recession 52. Fast flow of intake is concentrated there. A recirculation gas inflow port 9 on a terminal end of a recirculation gas introduction passage 8 is opened correspondingly to the portion. The contraflow of the recirculation gas from the recirculation gas inflow port 9 is prevented, while the gas is fed to the downstream side with certainty.