| 摘要 |
PURPOSE:To reduce the throttling loss at a nozzle hole of a subsidiary combustion chamber and to reduce the heat loss in a main combustion chamber, by specifying the ratio between the major diameter and the minor diameter of the openings at the opposite ends of the nozzle hole in an engine in which the outlet angle theta1 of the nozzle hole on the side of the main combustion chamber and that theta2 of the nozzle hole on the side of the subsidiary combustion chamber are selected to satisfy the relationship, theta2>theta1. CONSTITUTION:In an engine of the type having a subsidiary combustion chamber (subsidiary chamber), a subsidiary chamber 2 is formed in a cylinder head 4 in the manner that it is communicated with a main combustion chamber 1 via a nozzle hole 3, and a fuel injection valve 5 and a glow plug 6 are provided for the subsidiary chamber 2. Providing that the outlet angle of the nozzle hole 3 at the opening located on the side of the main combustion chamber 1 is theta1 and that of the nozzle hole 3 at the opening located on the side of the subsidiary chamber 2 is theta2, the nozzle hole 3 is formed to satisfy the following relationship, theta2>theta1. Further, providing that the major diameters of the openings at the opposite ends of the nozzle hole 3 are a2, a1 and the minor diameters are b2, b1 respectively, the nozzle hole 3 is formed also to satisfy the relationship, a2/b2>a1/b1. With such an arrangement, it is enabled to reduce the throtling loss of the nozzle hole 3 and to smooth the gas flow from the subsidiary chamber 2 to the main combustion chamber 1. |
