As well as the fuel and emissions benefits of stop-start systems, ADT can improve cold engine starts, reduce loading and wear on engine components during start-up, and make start-up faster, says Jacobs.
During testing, the ADT device reduced engine shake by up to 90% during shutdown.
The device is automatically activated by the engine control unit (ECU) whenever the engine shuts down or starts up, and works by keeping the engine valves open and the cylinders decompressed.
When switching off the engine, it coasts to a smooth shutdown without causing the cab to shake. When starting up, the engine is kept in a decompressed state which decreases cranking torque by 40% and allows the engine to spin up to twice its normal speed for smoother starting, faster priming of the fuel system, and decreased wear on the starter gear, fly wheel and other components.
Jacobs says this can also enable the use of smaller and lighter batteries, cables and starter.
As the engine can turn over while decompressed, ADT also improves start-ups in cold temperatures by enabling the engine to reach its critical compression ignition speeds. When combined with supplemental air inlet heaters, ADT also enables the engine cylinders to be pre-warmed without the engine load from compression. When high cranking speed is reached, the engine compression is reactivated and cylinder fuelling begins.
Steve Ernest, VP of engineering and business development at Jacobs Vehicle Systems, says: “ADT is another development of Jacobs’ well-proven valve actuation technologies to deliver another set of benefits.
“Some OEMs will be interested in ADT because it enhances vehicle refinement by eliminating engine-shake and cabin-shake. Other customers – particularly those whose vehicles endure heavy stop-start cycles – will welcome the reduced component load, fuel economy and emissions advantages.” Clink the link below to see a video on how ADT works: