| 摘要 |
Several embodiments of internal combustion engines each having an arrangement for increasing turbulence in the combustion chamber under at least certain load and/or speed conditions so as to permit the use of a relatively simple spark advance mechanism. In each embodiment, the flame propogation is controlled by controlling the degree of turbulence to achieve the desired effect. The turbulence is generated by causing induction of at least a portion of the engine charge requirements through a relatively small cross sectional area auxilliary induction passage. Because of the small cross sectional area, high flow velocities are generated which are maintained in the combustion chamber. In accordance with certain embodiments of the invention, the degree of turbulence is controlled by either shunting some of the air flow through the main induction passage or by introducing controlled amounts of exhaust gas products. In accordance with another embodiment of the invention, the associated distributor is provided with two pairs of contact points each of which provides a different spark advance and a control circuit for selecting the appropriate set of contact points to set the particular running condition of the engine. |
