| 摘要 |
PURPOSE:To generate a swirling stream of air to a sufficient degree by a method wherein a throttle valve in a passage establishing communication between a swirl chamber and a main combustion chamber is operated such that the sectional area of passage of a piston at the time of its expansion stroke becomes larger than that at the time of its compression stroke. CONSTITUTION:A throttle valve 7 is provided in the passage 5 between a swirl chamber 4 and a main combustion chamber 3 provided in a cylinder head 1' and a spring 8 is provided to energize the valve 7 in its opening direction. When a piston 2 shifts to its compression stroke, the air within a cylinder 1 is compressed and one half of the air enters the swirl chamber 4 at the end of the stroke. During the above process, the valve 7 is in a condition shown by the broken line choking the sectional area of the passage of the piston and so the flow velocity of the air becomes so high that a strong swirling stream of air generates in the direction of the arrow. Next, when the piston shifts to its expansion stroke, the valve 7 opens the passage 5 through a cam 9 and therefore, the expansion pressure of an ignited fuel in the swirl chamber 4 is transmitted to the main combustion chamber 3 so that the expansion pressure acts on the piston 2 effectively without being delayed from the expansion stroke of the piston. |
