Tumble type variable streamline generating device for e.g. petrol engine of motor vehicle, has seat with projecting part formed of revolution surfaces whose dimensions do not modify discharge of intake flow during high lifting

摘要

The device has a seat (3) with a projecting part inserted in an end (10) of an intake pipe (1) and formed of revolution surfaces (31, 32). The surface (31) is projected on a portion of circumference in an incidence zone of intake flow from the pipe. The surface (32) is projected on a remaining part of the circumference in a tangency zone of the flow. The surface (31) deflects the flow in a direction corresponding to inverse tumble during low lifting of intake valves (2). The dimensions of the surfaces do not modify the discharge of the flow along a pipe's symmetry axis during high lifting.