FINE SWIRL FLOW GENERATING DEVICE OF SWIRL CHAMBER TYPE COMBUSTION CHAMBER FOR DIESEL ENGINE

摘要

PURPOSE:To generate a large volume of fine swirl flows in a combustion chamber in which a fine swirl flows generating recessed part is provided on the inner peripheral surface of a nozzle hole communicating a swirl chamber with a main combustion chamber by forming the recessed part of a specially shaped ring-groove formed over the entire periphery in the circumferential direction on the inner peripheral surface of the nozzle hole. CONSTITUTION:With a swirl chamber type combustion chamber 12, a main combustion chamber 1 is communicated through a nozzle hole 2 with a swirl chamber 3, and a fuel injection nozzle 4 faces the swirl chamber 3. Further, a fine swirl flows generating recessed part 5 is provided on the inner peripheral surface of the nozzle hole 2. In this case, the fine swirl flows generating recessed part 5 consists of a ring-groove 10 formed over the entire periphery in the circumferential direction on the inner peripheral surface of the nozzle hole 2, and the ring-groove 10 is shaped so that fine swirl flows are generated over the entire periphery of compressed air flow 6 passing through the nozzle hole 2 in the compression stroke, and fine swirl flows are generated over the entire periphery of expanded gas flow passing through the nozzle hole 2 on the expansion stroke. That is, the ring-groove 10 is formed, at about intermediate position in the axis 14 direction of the nozzle hole 2, into a ring-like form of circular cross section, along a plane intersecting the axis 14 of the nozzle hole 2 at a right angle.