Heavy-duty vehicle component manufacturer Jacobs Vehicle Systems has launched its new High Power Density Engine Brake for vehicle and engine manufacturers, announcing the technology at the IAA Commercial Vehicle show in Hannover, Germany.
Jacobs’ HPD Engine Brake increases the performance of traditional compression release braking over the engine’s entire operating range and can double braking performance at lower rpm. The technology can provide large engine displacement braking power in small and medium displacement diesel and natural gas engines.
The system is designed to be quiet in operation and is fully integrated into the engine’s overhead design. It can assist with exhaust aftertreatment thermal management by preventing the catalyst from cooling during descents.
By increasing engine braking performance at lower engine speeds the HPD Engine Brake can improve thermal management and match industry trends toward downspeeding and downsizing engines, according to Jacobs.
Engine braking performance is becoming increasingly important because key strategies for improving fuel efficiency include reducing the natural slowing of the vehicle caused by wind resistance, engine, drivetrain, and rolling resistance from the tires, says Jacobs.
Jacobs’ HPD Engine Brake transforms the four-stroke engine into a two-stroke compression device by deactivating the main intake and exhaust valve events and supplementing with two-stroke valve events. Whereas a conventional engine brake has one compression release and one brake gas recirculation event per cam rotation, this innovative and patented two-stroke technology achieves two braking events per cam rotation. It is fully variable with controlled boost modulation, which allows the driver to achieve the right balance between retardation, speed and efficiency.
“The majority of European trucks still use hydraulic driveline retarders, which are dependent on vehicle speed for effectiveness, and are typically 175 kg heavier, with a corresponding penalty for the vehicle’s payload capacity,” said Sergio Sgarbi, Jacobs Vehicle Systems president. “The Jacobs HPD Engine Brake can cope with those lower speeds, eliminating the need for a driveline retarder and becoming the primary choice in secondary braking.”