| 摘要 |
PURPOSE:To lower the specific fuel consumption of an engine, by reducing the restriction loss at a subsidiary-chamber nozzle hole communicating a main combustion chamber and a subsidiary combustion chamber with each other by forming a cut-away portion in the inner wall surface of said nozzle hole at the portion thereof located away from the center line of a cylinder and in the vicinity of the opening on the side of the main combustion chamber. CONSTITUTION:In an internal combustion engine, in which a fuel injection valve 5 and a glow plug 6 are disposed in a subsidiary combustion chamber 2 that is formed in a cylinder head 4 such that its upper half is shaped in a spherical form and its lower half is shaped in the form of a truncated cone and the subsidiary combustion chamber 2 is communicated with a main combustion chamber 1 via a subsidiary-chamber nozzle hole 3, the nozzle hole 3 is shaped to satisfy the following relationship, theta1<theta2, where theta1 is the outlet angle of the nozzle hole 3 at its opening located on the side of the main combustion chamber 1 and theta2 is the outlet angle of the nozzle hole 3 at its opening located on the side of the subsidiary combustion chamber 2. Further, a straight cut-away portion 10 is formed in the inner wall surface of the nozzle hole 3 at the portion thereof located away from the center line B of the cylinder and in the vicinity of the opening on the side of the main combustion chamber. With such an arrangement, it is enabled to lower the specific fuel consumption of the engine by reducing the restriction loss at the nozzle hole 3. |
