| 摘要 |
<p>PURPOSE: To provide a connecting structure for a branch pipe in a high pressure fuel manifold wherein thickening except in a seal part is avoided to increase rigidity of the seal part and to enable also a number of part items to decrease. CONSTITUTION: In a peripheral surface of a main pipe 1 having a circulating path 2 in the inside to be composed of cylindrical extrusion mold material of thickening, an integrally protruding part 10 protruded in the radial direction is provided with a space apart in the axial direction, to form a high pressure fuel manifold. An opening hole 12 and through hole 3 communicating with the circulating path 2 are drilled in the protruding part 10, and a screw hole 12a in an internal peripheral surface of the opening hole 12 and a pressure receiving seat surface 3' in a bottom surface of the opening hole 12 are formed respectively. In this high pressure fuel manifold, a pressing seat surface 18 of a connection head part 6 in an end part of a branch connector 5 penetration-provided with a flow path 20 is brought into contact with the receiving pressure seat surface 3' by screwing a nut 7 to a screw 12a, to connect branch connectors 5, 5' to the high pressure fuel manifold 11. A thin wall steel pipe is secured to an internal peripheral surface of the circulating path 2 by diffusion or brazing, to prevent internal pressure fatigue destruction caused by a flaw, stripe in the axial direction generated at extrusion work time and groove part as start point, and to improve pressure resistance.</p> |
