摘要:
An engine charge control system operates by initially reducing power from full load by retarding exhaust valve (20) closing timing to increase exhaust gas charge dilution up to the limit for efficient operation. Further load reductions are made by reducing charge mass without increased dilution via alternative steps such as throttling (in conjunction with intake check valves or using individual cylinder valves) or retarding intake valve (19) opening timing without throttling. Partial substitution of external charge dilution is also contemplated.
摘要:
An engine charge control system operates by initially reducing power from full load by retarding exhaust valve (20) closing timing to increase exhaust gas charge dilution up to the limit for efficient operation. Further load reductions are made by reducing charge mass without increased dilution via alternative steps such as throttling (in conjunction with intake check valves or using individual cylinder valves) or retarding intake valve (19) opening timing without throttling. Partial substitution of external charge dilution is also contemplated.
摘要:
An intake venting system comprising a plurality of intake passages (22). Each of the intake passages (22) leads to a respective cylinder (12) in an engine. A reed valve (24) is disposed in and attached to each intake passage (22). Each of the reed valves (22) allows fluid flow towards the respective cylinder (12) and obstructs fluid back-flow in the reverse direction. An intake valve (20) is seated in each of the intake passages (22) between the reed valve (24) therein and the cylinder (12) to which the respective intake passage (22) leads. A bypass port (26) is located on each intake passage (22) so that each bypass port (26) communicates with a trapped volume (28) defined by the portion of the intake passage (22) between the reed valve (24) and intake valve therein (20). A control valve (32) is connected to each of the bypass ports (26), with the control valve (32) enabling communication between a predetermined pair of the trapped volumes (28) during a portion of the engine cycle when the pressure in one of the pair of trapped volumes (28) exceeds the pressure immediately upstream thereof, and the pressure in the other of the pair of trapped volumes (28) is less than the pressure in the one of the pair of trapped volumes (28).
摘要:
An intake port pressure control apparatus (20) comprises an intake passage (32) leading to a cylinder (22) in an engine, and a check valve (34) in the intake passage to allow fluid flow toward the cylinder and obstruct fluid back-flow in the reverse direction. A bypass port (38) is located on the intake passage so that the bypass port communicates with a trapped volume (36) defined by the portion of the intake passage between the check valve and intake valve. The intake port pressure control apparatus further comprises a control valve means (54) having an outlet passage (55,58), a secondary passage (56,59), and an actuating means (57) enabling communication between the outlet passage and secondary passage. The actuating means further enables active adjustment of the flow area of the flowpath between the secondary passage and outlet passage throughout a range of engine operating conditions. The outlet passage is connected to the bypass port, and the secondary passage is connected to a secondary air source. The control valve means enables a controlled air flow from the secondary air source into the trapped volume when the intake valve is closed.