Patent ID: 8826891
Filing Date: 2014-09-09
Classification: F02D,Y02T

Abstract:
1. A control apparatus for an internal combustion engine, comprising: a valve stop mechanism that is capable of switching each operational state of an intake valve and an exhaust valve between a valve operating state and a valve closed/stopped state; and a controller that is configured to: determine whether or not a failure concerning a stopping operation of the intake valve from the valve operating state to the valve closed/stopped state has occurred; obtain a negative torque of an internal combustion engine; and determine whether or not a failure concerning a stopping operation of the exhaust valve from the valve operating state to the valve closed/stopped state has occurred, on a basis of a magnitude of the negative torque of when an execution request for a fuel cut that is accompanied by a valve stop request to switch each operational state of the intake valve and the exhaust valve from the valve operating state to the valve closed/stopped state has been issued, in a case in which it is determined that a failure concerning the stopping operation of the intake valve has not occurred, wherein the controller determines that a failure concerning the stopping operation of the exhaust valve has occurred, when a torque difference of a current negative torque, with respect to a negative torque of the internal combustion engine in a case in which each stopping operation of the intake valve and the exhaust valve from the valve operating state to the valve closed/stopped state has been normally performed, is a minus value, and when an absolute value of the torque difference is larger than or equal to a predetermined first determination value, wherein the controller is further configured to obtain an engine speed fluctuation or a torque fluctuation of the internal combustion engine, and wherein the controller determines that a failure concerning the stopping operation of the exhaust valve has occurred, when the engine speed fluctuation or the torque fluctuation is larger than a predetermined second determination value, in a case in which the torque difference is a minus value and the absolute value of the torque difference is smaller than the first determination value.