Exhaust manifold pipe weld assembly

摘要

An exhaust manifold for an internal combustion engine includes one or more pairs of pipe members. Each pipe member has a downstream end portion, and includes along its downstream end portion a side wall in opposing relation with, and concave with respect to, the side wall of the other pipe member of the pair. The pipe members are joined at only two contacting areas of their respective downstream end portions. A gap is defined by the opposing concave side walls in which the side walls expand and contract while heating and cooling. Each of the pair of pipe members includes an outer pipe and an inner pipe disposed within the outer pipe. The inner pipe contacts the outer pipe at three contacting areas that are spaced from each other on the outer pipe so that an air-filled space at least partially separates the inner pipe and the outer pipe. Exhaust gases from the internal combustion engine are conveyed through such pairs of pipe members downstream to one or more exhaust pipes.