| 摘要 |
<p>A core structure includes a plurality of flat tubes (5) and a plurality of corrugated inner fins (10; 20; 30). Each corrugated inner fin (10; 20; 30) has top portions (10a) for being fixed to an inner surface of an upper wall portion (5a) of the tube (5), bottom portions (10b) for being fixed to an inner surface of the lower wall portion (5b) thereof, and slanted portions (10c) for connecting the top portion (10a) with adjacent bottom portions (10b) thereof. The corrugated inner fin (10; 20; 30) has first corrugations (N1; N4) located at both end sides of the corrugated inner fin (10; 20; 30) and second corrugations (N2; N5) located between the first corrugations (N1), where each of the first and the second corrugations (N1, N2; N4, N5) have the top portion (10a) and the adjacent slanted portions (10c) and project from the bottom portions (10b). The first corrugations (N1; N4) have is set to be smaller in a front-back directional length of the corrugated inner fin (10; 20; 30) than a front-back directional length of the second corrugations.</p> |
