Throttle for external ignition IC engine - has profiled section to produce supersonic velocities at low loads to improve combustion

摘要

The engine is controlled by a throttle (1) in a suction manifold (4) which can be part of a carburetter. Fuel is added to the air stream upstream of the throttle. One side (41) of the throttle blade has a profiled cap (11) placed over it. The profile is such that when the throttle is partly closed the cap and the side of the manifold form a convergent divergent nozzle (8, 12). The fuel air mixture passing through this reaches supersonic velocities in the convergent section. The supersonic velocity breaks up unvapourised fuel particles thus improves the homogeneity of the mixture at low loads.