| 摘要 |
According to first quantity of state control, a rich spike is executed while actuating a WGV so as to decrease turbocharging pressure, and after completion of the rich spike, the WGV is actuated to raise the turbocharging pressure again, the combustion air-fuel ratio is adjusted to the theoretical air-fuel ratio while suppressing an air amount by a throttle so as not to vary shaft torque until the turbocharging pressure is restored, and upon the turbocharging pressure being restored the air amount is increased by the throttle and the combustion air-fuel ratio is returned to a lean air-fuel ratio. According to second quantity of state control, a rich spike is executed while actuating the WGV so as to maintain the turbocharging pressure, and after completion of the rich spike, the air amount is increased by the throttle and the combustion air-fuel ratio is returned to a lean air-fuel ratio. |
| 主权项 |
1. A control apparatus for an internal combustion engine that controls an internal combustion engine that has a turbocharger provided in an intake passage, an actuator which changes an operating state of the turbocharger to adjust a turbocharging pressure, a throttle provided downstream relative to the turbocharger in the intake passage, and a catalyst having a NOx storage-reduction capacity which is provided in an exhaust passage, and that is an internal combustion engine which is capable of lean burn operation according to a predetermined air-fuel ratio that is leaner in fuel than a theoretical air-fuel ratio,
the control apparatus configured to during execution of the lean burn operation, execute a rich spike that supplies a reducing agent to the catalyst by decreasing an air amount by means of the throttle and also making a combustion air-fuel ratio richer in fuel than the theoretical air-fuel ratio, and in a case where a timing arrives for executing the rich spike in an operating region in which turbocharging by the turbocharger is performed, select, between execution of first quantity of state control and execution of second quantity of state control, the one which results in a smaller fuel consumption quantity, wherein the first quantity of state control is configured to execute the rich spike while actuating the actuator so as to decrease a turbocharging pressure relative to a turbocharging pressure before execution of the rich spike, and after completion of the rich spike, actuate the actuator to raise the turbocharging pressure again, adjust the combustion air-fuel ratio to the theoretical air-fuel ratio while suppressing an air amount by means of the throttle until the turbocharging pressure is restored to a pressure that is equal to the turbocharging pressure before execution of the rich spike, and upon the turbocharging pressure being restored to a pressure that is equal to the turbocharging pressure before execution of the rich spike, increase the air amount by means of the throttle and return the combustion air-fuel ratio to the predetermined air-fuel ratio, and wherein the second quantity of state control is configured to execute the rich spike while actuating the actuator so as to maintain the turbocharging pressure at a pressure thereof prior to execution of the rich spike, and after completion of the rich spike, increase the air amount by means of the throttle and return the combustion air-fuel ratio to the predetermined air-fuel ratio. |
