PURPOSE: To form a heat exchanging pipe having a thin pipe wall and to reduce the cost by joining each other numerous tongue-like fins after their forming to the face of the part becoming the respective pipe outside of a strip-like plate stock and the extruded section equipped with a side wall and partition wall on one face of the horizontal wall.
CONSTITUTION: A plate stock 1 and the extruded section 9 having the same width length as those of the plate stock 1 and having two side walls 7 and vertical partition wall 8 on one face of the horizontal wall 6 are prepared. Numerous tongue-like fins 4 and 12 are the provided in a shaving and erecting shape on the face of the part becoming in the respective pipe outside of the plate stock 1 and and extruded section 9. the plate stock 1 and extruded section 9 providing numerous tongue-like fins 4, 12 on the face of the part becoming in the pipe outside are combined by facing the face becoming in the respective pipe inside each other to braze the tip edge parts of three partition walls 8 and both side walls 7 to the face of the plate stock 1 with vacuum brazing method. Four fluid passages 14 are thus formed at the inner part to obtain the heat exchanging pipe 15 providing numerous tongue-like fins 4, 12 on the upper and lower faces.
WATANABE SHOICHI
WAKABAYASHI NOBUHIRO
OGASAWARA NOBORU
