Exhaust gas recirculation device for internal combustion engine

An exhaust gas recirculation device for an internal combustion engine, comprising an EGR pipe for recirculating exhaust gas to an intake channel from an exhaust channel immediately after an exhaust gas purification device provided midstream of the exhaust channel in the vicinity of a cylinder block of the internal combustion engine, wherein:

• a first connection part that connects the exhaust channel immediately after the exhaust gas purification device and the EGR pipe is provided to an upstream side of the EGR pipe;
• a second connection part that connects the EGR pipe with a device or another pipe leading to the intake channel is provided above the first connection part to a downstream side of the EGR pipe;
• the exhaust gas purification device expands in a longitudinal direction due to heat input, and as a result, the second connection part has stress concentration higher than the first connection part;
• the EGR pipe extends substantially upwards in a longitudinal direction from the first connection part or extends in a substantially horizontal direction at a side of the second connection part, and has a plurality of curved parts between the first connection part and the second connection part;
• a narrowest-angle curved part is a single part that is curved at the narrowest angle among the plurality of curved parts is disposed at a position at which a distance from the first connection part and a distance from the second connection part are substantially equal, and wherein the narrowest-angle curved part is provided between a part of the EGR pipe that extends substantially upwards in the longitudinal direction from the first connection part, and a part of the EGR pipe that extends substantially horizontally from the second connection part;
• and
• a number of curved parts disposed between the narrowest-angle curved part and the second connection part is greater than a number of the curved parts disposed between the first connection part and the narrowest-angle curved part, wherein the curved parts bend so as to disperse the stress concentration from the second connection part.