UniAir is another typical example of Schae ler technologies drivers arguably never get to see but that save them money provide comfort and bene t the environment It s the world s rst electrohydraulic system for fully variable control of the engine valves in gasoline and diesel engines So far the system is exclusively utilized on the intake side of gasoline engines says Mi chael Haas 56 who is in charge of the variable valve train product line at Schae ler However there are no limits to its utilization in diesel en gines or on the exhaust side With UniAir the engine can always op erate in the optimum e ciency range Fuel economy with UniAir in combina tion with downsizing improves by up to ten percent At the same time pow er output can be raised by ten percent and torque in the lower engine speed range by up to 15 percent In addi tion vehicle occupants bene t from a more comfortable ride especially in dense tra c UniAir is not only e cient in terms of fuel economy and emissions but enhances driv ing pleasure as well due to its fast response says Nicola Morelli 48 Director System Development UniAir adding that UniAir responds faster to the driver s demands particularly at lower speeds UniAir technology is invented in 1999 by Centro Ricerche Fiat CRF However the Italians lack the know how for development industrial ization and manufacturing that is necessary to put the system into pro duction so they turn to Schae ler to obtain it Together the automobile manufacturer and the automotive supplier by 2009 develop the prod uct which Schae ler has since been manufacturing and marketing as fully variable valve control thanks to an exclusive license Initially sold THE FULLY VARIABLE UNIAIR VALVE CONTROL to FCA Fiat Chrysler Automobiles the system dubbed as MultiAir operates in engines of Alfa Romeo Fiat Chrysler and Jeep It s the core element of the TwinAir two cylin der family We ve made the system salable Haas agrees because there s a world of di erence between inventing and industrializing This is due to the many components be longing to UniAir as well as the precision in the microscopic range Manufacturing requires appropri ate production processes that only Schae ler masters says Haas We re the hydraulics specialists with the requisite precision plus the capability of manufacturing the right components at the lowest pos sible costs The rst UniAir engine in 2009 is the Fiat four cylinder from the Alfa Romeo MiTo 1 4 a F I R E unit Fully Integrated Robotized En gine that has been completely as sembled by robots A fully variable valve control system speci cally developed for Jaguar Land Rover has recently been intro duced in the Ingenium four cylinder engine family combined for the rst time with two hydraulic camsha ad justers As a result for instance the engine can be shut o with low vibra tions in start stop mode and instantly restart Fast control of the valves with cyclical precision is another advan tage It allows spontaneous torque development without impairing e ciency due to excessive retardation in ignition timing Now Schae ler is working on mak ing UniAir even more e cient Con ceivable for instance is a reduction of components as well as the uti lization of enhanced combustion strategies There s still ample de velopment potential says Haas We re also thinking about an in tegration of fully variable UniAir valve control directly in the cylin der head In conventional valve control the cams of the rotating intake camsha cause the valves to open and close The air required for combustion is controlled by the position of a throttle valve The disadvantage of this type of valve control is that timing is opti mized for a speci c load condition of the engine Even VCT variable cam adjustment cannot reflect all the con tinually changing driving conditions especially not at the frequently re quired pace As a result the engine does not run e ciently in all ranges By contrast Schae ler s fully vari able UniAir valve control always opti mally adjusts to changing power requirements THE AUTHOR Roland Löwisch a free lance motor journalist from Hamburg is always curious about the latest technology developments in the eld of cars and engines For his research he delved into the special topics of wet and dry dual clutches and fully variable valve control 55 in motion

Hinweis: Dies ist eine maschinenlesbare No-Flash Ansicht.
Klicken Sie hier um zur Online-Version zu gelangen.