PLATE FIN AND METHOD OF FITTING PLATE FIN AND TUBE TOGETHER

摘要

PURPOSE:To facilitate fin forming operation, by forming a flared portion having an inner diameter larger than the maximum tolerable diameter of a tube and a punched portion having a top inner diameter smaller than the maximum tolerable diameter of the tube contiguously with each other at the marginal portion of a hole formed in a plate fin. CONSTITUTION:A flared portion 4 and a punched portion 5 are formed contiguously at the marginal portion of a hole 3 formed at the central portion of a plate section 1 of a plate fin so as to receive a tube 2 therein. The flared portion 4 is a wall rising upward from the plate section 1 at an angle smaller than 90 deg.. The inner diameter of the flared portion 4 on the side of the plate section 1 is made greater than the maximum tolerable diameter of the tube 2 while that of the flared portion 4 at its top is made smaller than the maximum tolerable diameter of the tube 2. The punched portion 5 is a cylindrical wall rising substantially upright from the plate section 1 so that it extend along the outer wall surface of the tube 2.