| 摘要 |
PURPOSE:To promote the mixing with air in a main combustion chamber equipped with a long and narrow state recessed part appearing in a subchamber jet, by forming an angle, produced between a side wall of the recessed part and a plane at a right angle with the center line of a piston, to 90 deg. or less. CONSTITUTION:A rectangular recess shaped with the side of a subchamber jet 7 to a semicircle is formed to the top surface of a piston 2, then the semicircle and a side wall connected to the semicircle are arranged such that an angle theta formed by the side wall of tye recess and a plane at a right angle with the center line A-A of the piston is <90 deg.. In this way, burned and unburned gases inflowing from a subcombustion chamber flow into the recess and can be prevented from an outflow to a small gap part formed between the top surface of the piston 2 and the bottom surface of a cylinder head. Accordingly, cooling and thermal loss of gas by a wall surface of the small gap part can be reduced further penetration of a jet stream can be improved then the mixing with air in a main combustion chamber, that is, the combustion can be promoted. In this way, fuel consumption, discharge of smoke and thermal loss can be decreased. |
