Patent ID: 8689770
Filing Date: 2014-04-08
Classification: F02D

Abstract:
1. A control system for engine braking for a vehicle powered by an engine, the engine having a plurality of cylinders and an intake valve and an exhaust valve associated with at least one of the cylinders, the intake valve opening the cylinder to an intake manifold and the exhaust valve opening the cylinder to an exhaust manifold, the control system comprising: an engine braking control; at least one exhaust valve actuator responsive to demands from the braking control for causing the exhaust valve to open; and the braking control being configured to command the exhaust valve actuator to substantially open and substantially close the exhaust valve at least three times during each engine cycle when the pressure within the exhaust manifold is greater than the pressure in the cylinder, a first braking event, a second braking event, and a third braking event; the exhaust valve also being substantially opened and closed during each cycle for release of exhaust gases in the exhaust stroke of the engine; wherein the engine is a four stroke engine wherein a crankshaft rotates 720 degrees for each complete cycle, and 0 degrees is TDC, the braking control is configured to command the exhaust valve actuator to cause the exhaust valve to substantially open and substantially close for the first braking event during some part of the cycle between crank angles of 500 and 630 degrees, and cause the exhaust valve to substantially open and substantially close for the second braking event during some part of the cycle between crank angles of 630 and 90 degrees, wherein the braking control is also configured to command the exhaust valve actuator to cause the exhaust valve to substantially open and substantially close for the third braking event during some part of the cycle between crank angles of 360 and 500 degrees.