PURPOSE: To form the heat exchange tube having upper and lower walls held in tight contact with inner fins by pressurizing the upper and lower walls of an inner finned tubular material from both upper and lower sides and deforming the upper and lower walls to a flat shape as a whole.
CONSTITUTION: The upper and lower walls of the inner finned tubular material is pressurized from both upper and lower sides and is deformed to the flat shape as a whole to form the heat exchange tube having the upper and lower walls held in tight contact with the inner fins. The ratio Lc/R of the width (Lc) of the flat tubular material before the pressurization deformation and the radius (R) of curvature of the arc-shaped upper and lower walls is specified to 0.05 to 0.2 and the ratio Hc/H of the spacing (Hc) between the outside surfaces in the transverse central part of the upper and lower walls of this tubular material and the spacing (H) between the outside surfaces of the edge parts on both sides of the upper and lower walls is specified to 0.8 to 0.98. The ratio Lc/Lf between the width (Lc) of the flat tubular material before the pressurization deformation and the width (Lf) of the flat tubular material after the pressurization deformation is specified to 0.95 to 0.99.
TATEGAMI TETSUYA
NAKADA KEIICHI
| JPS6454136A | 1989-03-01 | |||
| JPS6167531A | 1986-04-07 |