Jacobs Vehicle Systems, Inc.

Ryan Lilly

Matei Alexandru

Justin D Baltrucki

Gabriel Scott Roberts

Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

Systems and methods for counter flow management and valve motion sequencing in enhanced engine braking

A controller of an internal combustion engine receives a request to activate an exhaust brake subsystem and, in response thereto, activates the exhaust braking subsystem. The controller thereafter determines that at least one parameter of the exhaust system, an intake subsystem or both compares unfavorably with at least one threshold. When the at least one parameter compares unfavorably with the at least one threshold, the controller determines that the exhaust braking subsystem has failed. In embodiments, the determination that the at least one parameter compares unfavorably with the at least one threshold comprises a determination that backpressure in the exhaust system is lower than a backpressure threshold and/or a determination that boost pressure in the intake subsystem is higher than a threshold.

Method and apparatus for determining exhaust brake failure

A controller of an internal combustion engine receives a request for engine braking and, in response thereto, activates an exhaust braking subsystem. Additionally, after passage of a period of time, the controller further activates a compression release braking subsystem. The period of time is preferably selected to permit development of increased back pressure in an exhaust system of the internal combustion engine prior to activation of the compression release braking subsystem. Additionally, following activation of the exhaust braking subsystem, the controller may whether the exhaust braking subsystem has failed and, if so, cause the compression release braking subsystem to operate in a reduced braking power mode, for example at less than full braking power potentially down to and including no braking power.

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Manchester, CT, United States of America

Ryan Lilly