Engine braking controller

摘要

In one aspect of the invention, an engine is operated in a skip cylinder engine braking mode. In the skip cylinder engine braking mode, selected working cycles of selected working chambers are deactivated. Other selected working cycles of the selected working chambers are operated in a braking mode. Accordingly, individual working chambers are sometimes deactivated and sometimes operated in the braking mode while the engine is operating in the skip cylinder engine braking mode. Various methods for cylinder control are described, which improve fuel economy, catalytic converter performance, and vehicle NVH characteristics.

主权项

1. A method of controlling the amount of engine braking provided by an engine having at least one working chamber, the method comprising:
determining a desired amount of engine braking; and operating the engine in a skip cylinder engine braking mode that substantially delivers the desired amount of engine braking, wherein in the skip cylinder engine braking mode, selected working cycles of at least one selected working chamber are deactivated and other selected working cycles of the at least one selected working chamber are operated in a braking mode such that at least one working chamber is sometimes deactivated and sometimes operated in the braking mode, and wherein at least some of the working cycles operated in a braking mode, fuel is delivered to the working chambers operated in the braking mode, the working chambers operated in the braking mode are fired and the fired working chambers in the braking mode each generate a net negative torque.