| 摘要 |
<p>The invention discloses a positive-displacement engine. The main difference between the engine and the constant volume engine is that two nested pistons which are provided in a cylinder. The inner piston is joined to a connecting rod via a piston pin. The outer piston is provided with piston rings and is supported on the inner piston by springs. The change of volume in each stroke is different. During the exhaust stroke, the outer piston reaches the top dead point, the exhaust gas is nearly expelled entirely (the discharging ratio may be 95%~98% in theory), thereby the compression ratio is increased (=12). During the intake stroke, the outer piston produces inertial displacement at the end of intake, thus the air intake is increased, and the self-supercharge effect is achieved. The peak air pressure and the rising speed of it is reduced due to the elastic accumulated energy action of the outer piston. This can reduce the structural stress, cut down the self-weight of the engine, and improve the operation stability. The output torque is increased due to the rearward shift of the peak air pressure, thereby the efficiency and the performance of engine are improved.</p> |
