Intake and exhaust control apparatus for internal combustion engines
AssigneeMazda Motor Corporation
InventorsMitsuo Hitomi, Junsou Sasaki
Life of this patent
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Abstract
An intake-exhaust control system includes a mechanism for changing timings at which the open periods of intake and/or exhaust valves overlap. A control unit cooperates with the valve timing changing mechanism to cause it to change the timing stepwise so as to vary the valve overlap in time, or in degrees, in a plurality of steps according to engine operating conditions, such as engine speed and engine load. The valve overlap, when the engine operates under medium or moderate engine speeds, is varied so as to be larger or longer under medium engine loads than under higher or heavier and lower or lighter engine loads.
Claims16
An intake and exhaust control system for changing a valve overlap, in degrees, of an internal combustion engine having intake and exhaust valves, comprising:
- .
- timing means for changing a valve operation timing of at least one of the intake and exhaust valves of the engine;
- monitoring means for monitoring an engine speed and an engine load and generating signals representative of said engine speed and said engine load;
- and
- control means responsive to said signals for causing said timing means to change said valve operation timing so as to vary the valve overlap for medium engine speeds so that the valve overlap is larger under medium engine loads than under lower and higher engine loads.
An intake and exhaust control system for changing a valve overlap, in degrees, of an internal combustion engine having intake and exhaust valves, comprising:
- timing means for changing a valve operation timing of at least one of the intake and exhaust valves of the engine;
- monitoring means for monitoring engine speeds and engine loads and providing signals representative of engine operating speeds and engine operating loads;
- and
- control means responsive to said signals for causing said timing means to change said valve operation timing so as to make the valve overlap larger at middle engine operating loads than at high and low engine operating loads for a particular engine speed.
Dependencies are inferred from the claim text.