Abstract: A fluid distribution pipe includes an elongate tubular body and a spherical end form integral with the tubular body at an inlet end. The spherical fluid connection end of the fuel rail is formed by plastic deformation. A series of tools and motions is used while the tubing of the fuel rail is clamped in place to form the spherical end form at the inlet end of the tubing. The resulting spherical end form provides the necessary geometry and surface finish to provide a successful seal and flexible connection of the fuel rail with a fuel line with significant cost advantages over current prior art methods.

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.

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 fluid distribution pipe includes an elongate tubular body and a spherical end form integral with the tubular body at an inlet end. The spherical fluid connection end of the fuel rail is formed by plastic deformation. A series of tools and motions is used while the tubing of the fuel rail is clamped in place to form the spherical end form at the inlet end of the tubing. The resulting spherical end form provides the necessary geometry and surface finish to provide a successful seal and flexible connection of the fuel rail with a fuel line with significant cost advantages over current prior art methods.

Abstract: A precision fuel rail assembly for direct fuel injection comprising a plurality of formed parts first assembled and positioned loosely on a precision fixture, then joined (e.g. tack welded), by applying a BFM on all joints forming a “green” assembly and firing in a brazing oven, to produce a precision assembly formed from stainless steel parts. A bracket defining a sole plate for the assembly may be formed as a continuous element or a plurality of individual fuel rail brackets. Flanged sockets are attached to the bracket at locations corresponding to the fuel injector locations on an engine bank. Bolt holes are provided along the centerline of the sockets and fuel injectors. The bracket supports a fuel distribution tube via saddle elements disposed between the bracket and the tube. A jump tube supplies fuel from the distribution tube to each socket.

Abstract: Apparatus and method for securing a fuel rail to a cylinder head of an engine wherein a plurality of passageways are formed through the fuel rail perpendicular to the longitudinal axis thereof. Securing members (e.g., bolts) are passed through the passageways and secured directly to the cylinder head. The bolts and injector sockets are preferably arranged in linearly spaced, alternating fashion along the fuel rail and lie along a common plane that intersects the longitudinal axis of the fuel rail.