DIESEL ENGINE NOZZLE SPRAY TIP Russian patent published in 1999 - IPC

FIELD: mechanical engineering; fuel system of diesel engines. SUBSTANCE: spray tip needle is provided with shutoff edge formed in intersection of two conical surfaces converging in direction of fuel flow. Throttling cone is made with preset deviation from roundness at least in one direction. Normalized section of surface is made convex with curvature whose radius exceeds half of diameter of cross section of throttling cone in maximum size. Additional cone made on spray tip needle forms throttling edge, at intersection with throttling cone, located on spray tip needle above line of mating of seat and well. Owing to decrease in side surface of throttling cone and resulting increase in contact stresses at interaction with seat and advance wear of throttling cone, functionally required size of throttling clearance S is provided. Angles α₂ and α₃ of conical surfaces forming shutoff edge are chosen to provide the following relationship: value of angle α₂ is smaller than value of seat angle ϕ by the value by which value of angle ϕ is smaller than that of angle α₃. EFFECT: increased service life and efficiency of spray tip. 3 cl, 3 dwg