HEAT EXCHANGER AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To solve a problem that the machining speed lowers and cutting chips are generated when a tube is enlarged while making a groove in the process for enlarging the tube of a heat exchanger and a problem that the machining is complicated and the cost increases when a heat exchanger tube having a composite groove is employed. SOLUTION: At the time of assembling a heat exchanger, a heat exchanger tube is deformed into a polygonal shape while being enlarged using a tube enlarging unit having a mechanism for rotating a tube enlarging tool by a simple method.