Patent ID: 7426955

Claim:
A core structure of a heat exchanger comprising: seat plates arranged opposite to each other with a predetermined space interposed therebetween, said seat plates being formed with tube holes; reinforcements connecting said seat plates at end portions thereof; tubes fixed at both end portions thereof by insertion into the tube holes; corrugated fins arranged between said tubes; and an upper tank and a lower tank attached to said seat plates, said tanks being connected by said tubes so that coolant can flow between said tanks through said tubes, wherein said tubes and said corrugated fins are alternatively arranged to form a core part, and a tube, which is arranged in at least an outermost position of said core part among said tube, being inserted at end portions thereof by insert members so that the insert members increase rigidity of the end positions of said tube inserted by the insert members and ensure flowing of the coolant between the tanks through said tube inserted by the insert members, wherein the insert members include two insert portions to be inserted in said tube and a connecting portion that connects the insert portions with each other in a state that a space formed between the insert portions can flow the coolant between an inside of said tube and an inside of said tank through the space when the insert member is inserted in said tube, and wherein the connecting portion is positioned out of said tube, and the insert portions being bent toward an edge side of the seat plate so that the connecting portion is dislocated from an overhead of an opening of said tube.