EXHAUST GAS HEAT EXCHANGING DEVICE

摘要

An EGR cooler includes an heat exchanging core which has a plurality of tubes and a first water passage, an upstream-side gas tank portion and a downstream-side gas tank portion that are respectively disposed on the upstream-side and the downstream-side to communicate with the tubes therein, a water tank portion that forms the first water passage and forms a second water passage which communicates with the water passage around the upstream-side gas tank portion, a double pipe portion that forms a gas passage which communicates with an inner portion of the upstream-side gas tank portion in the inside pipe and forms a water passage which communicates with the second water passage between the inside pipe and the outside pipe, a water inflow pipe that is connected to the outside pipe such that the cooling water flows into the water passage, and a water outflow pipe that is connected to the water tank portion such that the cooling water flows out from the first water passage.

主权项

1. An exhaust gas heat exchanging device comprising:
a heat exchanging core including a plurality of tubes through which an exhaust gas discharged from an internal combustion engine flows therein, the heat exchanging core defining a first water passage therearound, through which a cooling water flows; an upstream-side gas tank portion configured to form a passage which communicates with the plurality of tubes therein on a further upstream-side of the exhaust gas than the plurality of tubes; a downstream-side gas tank portion configured to form a passage which communicates with the plurality of tubes therein on a further downstream-side of the exhaust gas than the plurality of tubes; a water tank portion configured to form the first water passage by surrounding the plurality of tubes, the water tank portion forming a second water passage which communicates with the first water passage around the upstream-side gas tank portion; a double pipe portion including an inside pipe and an outside pipe, the inside pipe forming a gas passage which communicates with an inner portion of the upstream-side gas tank portion such that the exhaust gas flows through the gas passage, the double pipe portion forming an annular water passage which communicates with the second water passage between the inside pipe and the outside pipe such that the cooling water flows through the annular water passage; a water inflow portion connected to the outside pipe, through which the cooling water flows into the annular water passage; and a water outflow portion connected to the water tank portion, through which the cooling water flows out from the first water passage, wherein the upstream-side gas tank portion has an upstream-side open end portion which is internally fitted into the inside pipe of the double pipe portion.