Patent ID: 8229654

Claim:
An output restriction device for restricting engine output when a drive power output system for an internal combustion engine has an abnormality, the output restriction device comprising: an abnormality detection unit that detects an abnormality in the drive power output system; an initial restriction unit that restricts a tolerable range of the engine output to a first restriction region when the abnormality detection unit detects an abnormality in the drive power output system; and a secondary restriction unit that shifts the tolerable range of the engine output to a second restriction region, which has an upper limit lower than that of the first restriction region, in accordance with an operation history of the engine after the initial restriction unit restricts the tolerable range of the engine output to the first restriction region, wherein as the operation history of the engine, the secondary restriction unit uses a total workload of the engine in excess of the second restriction region after the initial restriction unit restricts the tolerable range of the engine output to the first restriction region to shift the tolerable range of the engine output from the first restriction region to the second restriction region in accordance with an increase in the total workload.