Core structure of heat exchanger

Abstract

A core structure includes a plurality of flat tubes and a plurality of corrugated inner fins. Each corrugated inner fin has top portions for being fixed to an inner surface of an upper wall portion of the tubes, bottom portions for being fixed to an inner surface of a lower wall portion thereof, and slanted portions for connecting the top portion with adjacent bottom portions thereof. The corrugated inner fin has first corrugations located at both end sides of the corrugated inner fin and second corrugations located between the first corrugations, where the first and the second corrugations has the top portion and the adjacent slanted portions and project from the bottom portions. The first corrugations are set to be smaller in a front-back directional length of the corrugated inner fin than a front-back directional length of the second corrugations.

1 . A core structure of a heat exchanger where a core part is arranged between a pair of tanks, the core structure comprising: 
 a plurality of flat tubes having an upper wall portion and a lower wall portion; and    a plurality of corrugated inner fins formed in a corrugated shape so that each corrugated inner fin has top portions for being fixed to an inner surface of the upper wall portion, bottom portions for being fixed to an inner surface of the lower wall portion, and slanted portions for connecting the top portion with adjacent bottom portions thereof, the corrugated inner fin having first corrugations located at both end sides of the corrugated inner fin and second corrugations located between the first corrugations, where each of the first and the second corrugations has the top portion and the adjacent slanted portions and project from the bottom portions, wherein    the first corrugations are set to be smaller in a front-back directional length of the corrugated inner fin than a front-back directional length of the second corrugations.    
   
   
       2 . The core structure according to  claim 1 , wherein the corrugated inner fin has at least one third corrugation which is smaller in the front-back directional length than the second corrugations and arranged between the second corrugations.  
   
   
       3 . The core structure according to  claim 2 , wherein 
 the number of the third corrugations located at a front side of the corrugated inner fin are larger than the number of the third corrugations located at a rear side of the corrugated inner fin.    
   
   
       4 . The core structure according to  claim 2 , wherein 
 the first corrugations, the second corrugations, and the third corrugation are arranged symmetrically with respect to the front-back direction of the corrugated inner fin.