DEVICE FOR CONTROLLING INTERNAL COMBUSTION ENGINE USING VARIABLE VALVE MECHANISM

摘要

Provided is a control device for controlling an internal combustion engine having a variable valve mechanism which can accurately and effectively identify a cylinder which has failed during an operation while preventing degradation of a catalyst. A fuel injection valve (26) for injecting a fuel is provided in each cylinder. The internal combustion engine includes variable valve mechanisms (18, 20) which can halt operations of an intake valve and an exhaust valve in a valve-closed state for each of the cylinders. The control device acquires a failure evaluation index value during an operation of the internal combustion engine (10) and detects a failure of at least one of the cylinders according to the failure evaluation index value. When a failure is detected, the control device executes a cylinder halt of a first cylinder unit formed by at least two cylinders, i.e., executes the fuel supply stop and the valve operation stop in the valve-closed state. After the cylinder halt, the halted cylinder is modified among a second cylinder unit formed by at least one cylinder and cylinder halt is executed. The cylinder which has failed is identified according to a change of a failure evaluation index value accompanying the modification of the halted cylinder.