Exhaust gas cooler and exhaust gas recirculation system for internal combustion engine

摘要

An EGR cooler (23) that cools EGR gas flowing through an EGR gas passage of an engine by heat exchange between the EGR gas and coolant flowing through a coolant outlet passage (32). The EGR cooler (23) includes: a housing (31) that is attached to one end of the engine and forms the coolant outlet passage (32); an exhaust gas recirculation pipe (33) that forms therein a part of an EGR gas passage of the engine in an inner periphery thereof and is supported by the housing (31) in which EGR gas flowing through the exhaust gas recirculation pipe (33) exchanges heat with coolant flowing through the coolant outlet passage (32); and an expansion joint (35) that is fixes the exhaust gas recirculation pipe (33) to the housing (31) and is elastically deformed to compensate for expansion/contraction of the exhaust gas recirculation pipe (33) with respect to the housing (31).