MANUFACTURE FOR INTAKE MANIFOLD

PURPOSE:To carry out joining without using any ring shaped brazing member so as to prevent cause of brazing failure by flame-spraying an aluminum brazing material on the outer circumferential surface of a branch pipe, and inserting the end part thereof into a hole formed on a tubular body to braze it. CONSTITUTION:An intake manifold is provided with an aluminum expanded member made tubular body 2 whose one end is opened and the other end is closed as a part of a plenum chamber. On the circumferential wall of the tubular body 2, a plurality of intake outlet 4 are formed, and also cylindrical outer projection parts 5 for connecting a branch pipe are provided integratedly around respective intake outles 4. When the branch pipe 6 is brazed on these projection parts 5, an aluminum brazing material is flame-sprayed on a raw pipe for forming the branch pipe 6, and the branch pipe 6 for forming a brazing material layer 23 is manufactured. And the tubular body 2 is so arranged as to point its cylindrical outer projection part 5 in vertical upward direction, and a proper flux is applied on the outer circumferential surface of one end part of the branch pipe 6. Thereafter, this one end part is filted in the hole 5b of the expanding pipe part 5a of the projection part 5, and then brazing is carried out.