JPS54112360A - Manufacture of heat transmitting tube - Google Patents

Abstract

PURPOSE: To continuously, simply work the spiral fin of Y-type section with large surface area around the outer surface of the tube blank, by combining the forming roll for the kerfed fin with the kerfing roll.

CONSTITUTION: At the first half zone of the thread rolling roll 1, the rolls 1a with comparatively narrow tip width are arranged at a fixed pitch; between these rolls 1a, are arranged the rolls 1b with sharp tip; and the tube blank 2 is somewhat obliquely thrusted so as to thread roll, forming the protruding part A whose top part is given with the kerf groove B at its approximate middle. In the meantime, at the latter half zone of the thread rolling roll 1, are arranged the fin forming rolls 1c ... getting wider and taller toward the backside, at the same pitch as the rolls 1a. These rolls 1c ... successively clamp and press the protruding part A so as to heap up forming the fin F whose middle part is provided with the kerf K. Next, the kerfing roll 1e, provided with sharp tip which is pushed into the kerf K at the middle part of the fin F, pushes the fin F so as to open to both sides, and the spiral fin F with Y-type secton is manufactured.

COPYRIGHT: (C)1979,JPO&Japio