Patent ID: 7568520

Claim:
An oil cooler contained in a radiator tank, the oil cooler comprising: a connecting pipe having an enlarged diameter portion; a heat exchange part having a plurality of elements which are piled up and flow oil through interior portions thereof, the elements being formed with a communicating passage for fluidically communicating with the interior portions of the elements; and a pipe connector formed with a first retaining portion that is seated on one side of a wall portion of the radiator tank to contain and fix at least a part of the enlarged diameter portion of the connecting pipe, and a second retaining portion that is inserted through a through-hole of the wall portion and an one end portion of the communicating passage to fix the heat exchange part and the wall portion at the other side of the wall portion, wherein the elements include an upper shell member having a cylindrical portion projecting outwardly and a lower shell member having a cylindrical portion projecting outwardly and having an outer diameter smaller than an inner diameter of the cylindrical portion of the upper shell member, the cylindrical portion of the lower shell member is fixed to the cylindrical portion of the upper shell portion of an adjacent element thereof to form the communicating passage by the cylindrical portions of the upper and lower shell members, wherein the communicating passage is fluidically plugged at the other end portion thereof by a patch plate having a seat portion directly contactable to an outer surface of the lower shell member, a cylindrical portion for fixing the lower shell member of an outermost element, and an annular groove formed between the seat portion and the cylindrical portion to receive the cylindrical portion of the lower shell member of the outermost element, and wherein the cylindrical portion of the lower shell member of the outermost element is clamped by a radially outwardly bent portion of the cylindrical portion and a bottom portion of the annular groove.