Patent ID: 7100547

Claim:
An intake-air control system for an engine employing a variable intake-air quantity mechanism that variably controls a quantity of fresh air entering the engine and a variable compression ratio mechanism that variably controls a compression ratio of the engine, comprising: sensor means for detecting engine operating conditions and the compression ratio; and control means configured to be electronically connected to the sensor means, the variable intake-air quantity mechanism, and the variable compression ratio mechanism for controlling the variable intake-air quantity mechanism based on the compression ratio as well as the engine operating conditions; the control means comprising: (a) a first required load setting means for setting a first required load based on the engine operating conditions; (b) an upper limit load setting means for setting an upper limit load based on the compression ratio; and (c) a second required load setting means for setting a second required load by limiting the first required load by the upper limit load, wherein the control means controls the variable intake-air quantity mechanism to satisfy the second required load, while controlling the compression ratio based on the engine operating conditions by the variable compression ratio mechanism.