COMBUSTION CHAMBER STRUCTURE FOR DIRECT INJECTING TYPE DIESEL ENGINE

摘要

PURPOSE:To more effectively diffuse injection fuel regardless of the difference of injection timing to improve the combustibility of fuel in the combustion chamber structure of a direct-injection type diesel engine. CONSTITUTION:A cavity 5 is formed on the top part of a piston 4 to provide an injection nozzle 7 for injecting fuel at high pressure toward the inner peripheral surface of the cavity 5. A bottlenecked part 8 composed by dividing the cavity 5 into two stages is formed in the opening vicinity of the cavity 5. Prutrudedly curved surf aces 9 and 10 curved outward are continuously formed along a peripheral direction on the inner peripheral surface of the cavity 5, and also are formed into two stages toward the bottom party 11 of the cavity 5 from the bottlenecked part 8. A protruded part 13 made into a truncated cone shape is formed on the bottom part middle of the cavity 5. Consequently injection fuel from the injection nozzle 7 strikes the respective protruded curved surfaces 9 and 10 to be positively reflected toward the inside of the cavity 5. Also fuel adherent to the respective protruded curved surfaces 9 and 10 is lessened, and moreover a swirling flow of air with the protruded part 13 as a center is strengthened to act on reflection fuel.