Kia develops new manual gearbox for future mild-hybrid models

MANILA: Kia has a new manual gearbox it’s calling ‘intelligent’ or an iMT that is set to be paired with future mild-hybrid models of the Korean automaker.

It will use a ‘clutch-by-wire’ system to increase fuel efficiency while reducing CO²emissions, and without losing driver engagement that’s naturally found in a conventional manual transmission.

In the place of a mechanical linkage, the iMT’s clutch operates purely electronically, and is integrated seamlessly with a 48V MHEV powertrain. The iMT works with the mild-hybrid starter generator (MHSG) to switch off the engine earlier than Kia’s Idle Stop & Go start-stop system when coasting to a full stop.

The chosen gear remains engaged even with the engine off. The engine restarts in the same gear as soon as the driver engages either the brake or accelerator thanks to the power provided by the MHSG. The transmission restarts the engine in neutral (with an open clutch) if the driver pushes the clutch pedal to change gear, or if the vehicle speed is too low for the current engaged gear.

Kia details its step-by-step operation below:

• The driver leaves the car in-gear as it starts to coast, gently slowing the car down (e.g. for a corner, junction, or traffic)
• While in-gear, the iMT sends an electronic signal to the gearbox and MHSG to seamlessly switch off the engine and open the clutch
• With the engine switched off, the car continues coasting, with the open clutch limiting deceleration and allowing the car to make the most of its kinetic energy
• As the driver pushes the accelerator to pick up speed, or engages the clutch to change gear, the MHSG restarts the engine in the driver’s selected gear, or in neutral (with an open clutch)
• Electric power from the MHSG and 48V battery instantly brings the engine and transmission up to the correct speed
• If the car drops below a certain speed, the engine restarts with assistance from the MHEV system, and the clutch closes, to avoid labouring the engine in the engaged gear.

“We are always looking at new ways to improve powertrain efficiency and performance, and the iMT is one such innovation. An automatic or a dual-clutch transmission suits a lot of drivers, but European drivers in particular still love changing gear for themselves. Alongside the increasing demand for electrified models, the iMT is a result of us exploring ways to electrify the ‘classic’ manual transmission,” said Dr Michael Winkler, Kia Head of Powertrain.

The iMT will be first seen in the Kia Rio EcoDynamics+, which is set to go on sale in Europe in the third quarter of 2020.

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Photos courtesy of Kia