Patent ID: 6932152

Claim:
A core structure of a heat exchanger, the core structure comprising: a plurality of tubes through which a heat exchange medium is to flow; a plurality of corrugated fins adhering to said tubes to advance radiation of heat from said tubes; and a plurality of seat plates arranged opposite to each other with a predetermined space interposed therebetween and having said tubes and said corrugated fins arranged alternately therebetween, said seat plates being provided with connection portions having main body portions and wall portions slanted from said main body portions toward said tubes and formed with tube holes through which said tubes are inserted to be fixed, wherein the connection portions also have first and second vulnerable portions which are thinner than said main body portions and said wall portions, in series on said wall portions, and absorb thermal stress of said seat plates against said tubes by bending, and said first and second vulnerable portions are formed at a position between said wall portions and the tube holes and a position between said main body portions and said wall portions, respectively.