|This electronically controlled eClutch closes the gap between automatic and manual transmissions. In addition, the eClutch makes the coasting function possible, which saves fuel. Click to enlarge.|
Bosch’s electronically controlled eClutch allows drivers of cars with a manual transmission to use first gear in stop-and-go traffic without engaging the clutch. If the powertrain is electrified, the electronically controlled clutch means that a combination of hybrid powertrain and manual transmission is now possible.
Up to now, it has only been possible to combine a hybrid powertrain with an automatic transmission, since it is not possible to coordinate a combustion engine and an electrical powertrain using a merely manual transmission. In this respect, the eClutch offers two advantages, Bosch says: (1) a manual transmission is possible in hybrid vehicles, and (2) the price of entry-level hybrids can be reduced, since a fully automatic transmission is no longer necessary.
With the eClutch, drivers simply use the brake and gas pedal in stop-and-go traffic, just as with an automatic transmission, without accidentally stalling the engine. In addition, the eClutch makes the coasting function possible, which saves fuel. Bosch estimates that the eClutch can reduce real fuel consumption in stop-start coasting by 10% on average.
Independently of the driver, the clutch decouples the engine from the transmission if the driver is no longer accelerating.
In terms of price, the eClutch costs significantly less than a conventional automatic transmission, and is thus an attractive alternative in the compact car segment, where price competition is difficult. Unlike a full-blown automatic transmission, the e-Clutch automates the clutch only, not the transmission. The clutch pedal transmits an electric signal to an actuator, which decouples the clutch.
For the stop-start coasting function, the Bosch system detects the driver’s easing of pressure on the gas pedal, decouples the engine from the transmission, and thus prevents the engine from consuming fuel. Drivers can already manually simulate this effect by disengaging the clutch on a downhill stretch.
In the future, the system will automatically assume this function, while stopping the engine at the same time.
As well as the stop-and-go function and the possibility of saving fuel, the eClutch offers a number of other functions. For example, it can be used to support gear shifts, making them smoother. A special sensor detects the start of a gear shift and adjusts engine speed. The result is a smooth, easy gear change.