Abstract: A fuel distribution tube for a direct injection fuel rail assembly includes an elongate cylindrical conduit, a plurality of first scalloped features that receive fuel injector sockets formed in the conduit, and plurality of second scalloped features that receive mounting bosses formed in the conduit. The scalloped features are designed to closely match the outer radii of the injector sockets and the mounting bosses. The scalloped features provide necessary dimensional control to injector sockets and mounting bosses and fuel passage from the fuel distribution tube to the fuel injector sockets. The scalloped features enable a leak test of the braze joints of the fuel rail assembly. By providing a direct injection fuel rail assembly that includes the fuel distribution tube having scalloped features formed in the conduit, optimization of true position location of fuel injector sockets and improved braze joints are enabled.

Abstract: A fuel distribution tube for a direct injection fuel rail assembly includes an elongate cylindrical conduit, a plurality of first scalloped features that receive fuel injector sockets formed in the conduit, and plurality of second scalloped features that receive mounting bosses formed in the conduit. The scalloped features are designed to closely match the outer radii of the injector sockets and the mounting bosses. The scalloped features provide necessary dimensional control to injector sockets and mounting bosses and fuel passage from the fuel distribution tube to the fuel injector sockets. The scalloped features enable a leak test of the braze joints of the fuel rail assembly. By providing a direct injection fuel rail assembly that includes the fuel distribution tube having scalloped features formed in the conduit, optimization of true position location of fuel injector sockets and improved braze joints are enabled.

Abstract: A method for assembling a direct injection fuel rail of an internal combustion engine includes the steps of: designing a fuel distribution tube having a first radius, mating a fuel rail component having a second radius that is different from the first radius with the fuel distribution tube, forming at least one projection point where the fuel rail component contacts the fuel distribution tube, consuming the at least one projection point during a resistance welding process, and forming a temporary bond between the fuel rail component and the fuel distribution tube. By intentionally mismatching the radii of fuel rail components, projection points are created that can be consumed during a resistance welding process. As the projection points are consumed, a temporary bond is formed between the fuel distribution tube and the fuel rail component, and a braze joint gap is optimized, which enables formation of a high quality braze joint.