Abstract: A mixing connector includes an intake passage, an EGR passage that fetches a portion of exhaust gas exhausted from an engine body to use as EGR gas, and that returns the EGR gas to the intake passage, and a merging section that connects the EGR passage to the intake passage so that longitudinal directions of the intake passage and the EGR passage intersect each other. An upstream side region located on an inlet port side of the intake passage from the merging section on an opposite wall surface configuring an inner surface of the intake passage and located on a side opposite to the merging section includes a first wall surface and a second wall surface which are sequentially arranged at an interval from the merging section side toward the inlet port, and a third wall surface projecting inward of the first wall surface between the first and second wall surfaces.

Abstract: A mixing connector includes an intake passage, an EGR passage that fetches a portion of exhaust gas exhausted from an engine body to use as EGR gas, and that returns the EGR gas to the intake passage, and a merging section that connects the EGR passage to the intake passage so that longitudinal directions of the intake passage and the EGR passage intersect each other. An upstream side region located on an inlet port side of the intake passage from the merging section on an opposite wall surface configuring an inner surface of the intake passage and located on a side opposite to the merging section includes a first wall surface and a second wall surface which are sequentially arranged at an interval from the merging section side toward the inlet port, and a third wall surface projecting inward of the first wall surface between the first and second wall surfaces.