| 摘要 |
PROBLEM TO BE SOLVED: To provide a venturi that facilitates mounting on various devices by reducing the length of the venturi without being associated with an excessive increase in pressure loss by devising the shape of a diffuser of the venturi.SOLUTION: A venturi includes: a nozzle part 11 that is provided in an intake passage 2 of an internal combustion engine 1 and restricts the passage area of the intake passage 2; a diffuser 12 that is provided in the intake passage 2 on the further downstream side than the nozzle part 11 spaced apart at an interval from the nozzle part 11 and increases the passage area of the intake passage 2 as going from the upstream side to the downstream side of the intake passage 2; an EGR merging part 14 that has an annular chamber 13 provided on the outer periphery of a clearance between the nozzle part 11 and the diffuser 12; and an EGR gas introducing part 16 that has an EGR gas introducing passage 15 communicating the EGR passage 6 with the annular chamber 13 of the EGR merging part 14. An inner wall surface 12a of the diffuser 12 is defined by a relaxation curve in which the radius of curvature is gradually reduced as going from the upstream side to the downstream side of the intake passage 2. |
