VAG - 1.4 TSI con Cilindri Disattivabili

[crabble]

Articolo interessante che parla della disattivazione di due cilindri anche per i motori 4 cilindri in linea

Small-Displacement Engines Integrating Cylinder Shutdown

By Tom Murphy

WardsAuto.com, Oct 4, 2010 9:10 AM

Rocker arm enables Eaton’s cylinder-deactivation system

Cylinder deactivation, a fuel-saving technology that has made V-8-powered pickups and SUVs more palatable for economy-minded buyers, is on the brink of resurgence.

With a corporate average fuel economy mandate of 35.5 mpg (6.6 L/100 km) taking effect in 2016, the two primary suppliers of electronically controlled cylinder-deactivation (CD) systems each tell Ward’s they have about 20 programs in the works with OEM customers.

ADVERTISEMENT

Together, Eaton Corp. and the Schaeffler Group’s INA division say they expect about 12 of those to reach production within the next three years. New V-8s are scarce among the likely prospects.

“Everybody’s interested in cylinder deactivation,” Bob Zito, director-engineering for engine components at Schaeffler Group USA Inc., says of OEM customers.

“There’s more money going into the powertrain for fuel economy these days than there was 10 years ago,” says David Genise, director of engineering-valvetrain at Eaton’s Vehicle Group, which manufactures 300 million engine valves annually.

Moving the technology forward is the trend toward downsized engines. Since 2004, CD has been heavily employed in OHV V-8 engines from General Motors Co. and Chrysler Group LLC for fullsize pickups, SUVs and cars.

GM says it has more than 2.7 million vehicles on the road globally with CD. In North America, Chrysler has produced 827,000 million CD V-8s for vehicles sold in the U.S. since 2004, according to Ward’s data.

Honda Motor Co. Ltd. also has the technology on a 3.5L SOHC V-6 and on 4-cyl. engines in hybrid applications.

Rocker arm enables Eaton’s cylinder-deactivation system.

The wave of new programs from Eaton and Schaeffler are focused on overhead-cam engines, mostly of the 4-cyl. variety.

For years, multi-valve dual overhead-cam engines were considered poor candidates for CD because they were twice as expensive – requiring twice the hardware – when compared with OHV engines.

That’s one reason Ford Motor Co., which has few OHV engines, has no CD programs in production, nor any planned, a Ford spokesman says.

But smaller engines make the cost differential less onerous, and new technologies are quelling some of the vibration issues associated with small-displacement engines, even those with just two cylinders.

Plus, the CD penetration rate is spurred along by mandates in the U.S. and elsewhere requiring higher fuel economy.

“I think that’s a primary motivation,” Eaton’s Genise says. “And in general if you look at fuel prices going up, it makes cylinder deactivation a salable point. Those two go hand in hand.”

Schaeffler’s INA division has exclusive agreement to market Fiat’s MultiAir valvetrain technology.

The technology idles unneeded cylinders during light-load driving cycles, generally boosting fuel economy between 6% and 12%.

Eaton’s CD system in GM’s 5.3L V-8 – a contract shared with Delphi Corp. – is marketed as Active Fuel Management.

Half the cylinders have unique 2-piece valve lifters, which incorporate two telescoping sections that can collapse into one another. An oil-pressure-activated locking pin in the lifters is engaged or disengaged – on command from the engine controller – based on driving conditions.

To deactivate half the cylinders, hydraulic pressure is used to unlock the pin, enabling the valve lifters' two sections to freely telescope into one another. As a result, camshaft motion is not translated to the pushrod, meaning intake and exhaust valves remain closed, until a throttle input causes them to reopen.

Looking forward, GM has hinted the 1.4L DOHC turbocharged I-4 in the new Chevrolet Cruze will offer AFM.

For Chrysler’s Multi-Displacement System on the 5.7L Hemi V-8 – available in many Chrysler Group vehicles – INA manufactures specially designed valve lifters that can selectively decouple the cam lift event from the respective poppet valves via electro-hydraulic actuation.

For new, high-revving OHC engines, Eaton and Schaeffler are introducing valvetrains that can operate with significantly more variability, even including CD if desired.

Eaton says its new variable valve-lift system can improve both fuel economy and power delivery, simply by switching valve-lift profiles. Combined with existing cam-phaser technology, for instance, the system can improve fuel economy up to 7%.

The technology switches modes the same way as the CD rocker arm and can be interchangeable, enabling different engines for diverse markets merely by changing the valvetrain components.

For customers who only want CD on future OHC engines, Schaeffler offers deactivating pivot elements.

But Zito argues that full variability of the valvetrain is the better route to achieve CD, while getting better performance and fuel economy, without a huge cost premium or the deactivating pivot element.

“If you can get deactivation for just a little more money because you put in all this other (valvetrain) variability, then the auto makers would take it,” he says.

As the supplier of Fiat Automobiles SpA’s MultiAir induction technology, Schaeffler has broad knowledge of fully variable valvetrains. Fiat pioneered the technology, introduced late last year in the Alfa Romeo MiTo in Europe and expected on as many as 1 million Fiat engines annually.

The first MultiAir engine arrives in the U.S. at the end of this year when the Fiat 500 goes on sale, powered by a 1.4L FIRE engine being built in Dundee, MI.

In addition, sources say Chrysler will offer MultiAir on a 2.4L 4-cyl. in midsize sedans and is considering it for the all-new 3.6L Pentastar DOHC 60-degree V-6 in the redesigned Jeep Grand Cherokee and other models. No word yet on whether those engines will integrate CD.

Through its relationship with Fiat, Schaeffler’s INA unit has exclusive rights to market the technology under the Uni-Air brand name to other auto makers, including supply of the patented valve actuators, solenoid

Da WardsAuto.com Small-Displacement Engines Integrating Cylinder Shutdown

[PaoloGTC]

Mi ricorda qualcosa :D:D

Qualcuno ha detto modulare CEM?

(vabbè, per l'idea, volevo dire...)

[jeby]

a me ricorda quando la punto di un mio amico, ogni tanto, andava a tre cilindri... per risparmiare, ovvio!

[owluca]

lo aveva gia' inventato la fiat ai tempi della dedra le cui guarnizioni della centralina non tenevano e quando pioveva 4-3-2-1 0.....km/h:oops:

p.s. mi ricordo quando al sabato ci siamo fermati al casello di carisio, proprio dove mio padre si era fermato in settimana con l'audi 80 (che la dedra"tentava" di sostituire)

causa grippaggio completo del cambio (quinta-quarta terza seconda prima ...solo folle )

il casellante e' scappato toccandosi i maroni attraverso le risaie e magari Paolo sa anche dirci dove si sia rifugiato:lol:

[PaoloGTC]

Credo sia quel tizio che ogni tanto se attraversi la Bassa ti spunta dall'argine della risaia, bardato tipo Commando, e se hai una Lancia ti riempie di piolettate sul cofano.

Ed io che pensavo fosse un vecchio tester Alfa scappato dalle prigioni sotterranee di Balocco.

Ecco chi è

[Uomo dell'Ovest]

Disattivazione cilindri anche sui 4 in linea? Beh non è una novità assoluta... lo faceva anche la nostra ypsilon. Però per riattivarli abbiamo dovuto spendere 500€ di centralina! Un twinair precoce!

[p.fina]

Volkswagen presents latest efficiency technology

World’s first cylinder shutoff system in four-cylinder TSI

Wolfsburg, 02 September 2011 - At the beginning of 2012 it will already be ready: Volkswagen’s latest efficiency technology, cylinder shut-off, will debut in the new 1.4 TSI engine. This is another large step for Volkswagen in terms of saving fuel in its models.

Volkswagen is the first manufacturer in the world to implement cylinder shut-off on a four-cylinder TSI engine in high-volume production. The primary goal of the high-tech system is to significantly reduce fuel consumption by temporarily shutting off two of the four cylinders during low to mid loads. In fact, cylinder shut-off reduces fuel consumption of the 1.4 TSI by 0.4 litre per 100 km in the NEDC driving cycle. When the Stop/Start functionality is integrated, which deactivates the engine in neutral gear, the savings effect adds up to about 0.6 litre per 100 km.

The greatest benefits of the cutting edge technology are realised while driving at constant moderate speeds. At 50 km/h, in third or fourth gear, savings amount to nearly one litre per 100 km. This new fuel efficient TSI will therefore also fulfil the future EU6 emissions standard effortlessly. High efficiency does not exclude driving comfort: even when running on just two cylinders, the 1.4 TSI – with its excellent engine balance – is still very quiet and low in vibration.

Cylinder shut-off is active whenever the engine speed of the 1.4 TSI is between 1,400 and 4,000 rpm and its torque is between 25 and 75 Nm. This applies to nearly 70 per cent of the driving distance in the EU fuel economy driving cycle. As soon as the driver presses the accelerator pedal sufficiently hard, cylinders 2 and 3 are reactivated unnoticed. Volkswagen utilises information from the gas pedal sensor to detect the driver’s mode of driving. If the driving exhibits a nonuniform pattern – e.g. while driving in roundabout traffic or in a sporty style on a country road – shut-off functionality is suppressed.

Volkswagen Media

[Ario_]

All'inizio del 2012, la Volkswagen farà debuttare sulla Golf 1.4 TSI da 140 CV il suo sistema di disattivazione dei cilindri: l'obiettivo è di ridurre in maniera significativa il consumo di benzina e le emissioni di CO2. In determinate situazioni di guida, con carico medio-basso, il quattro cilindri Volkswagen può funzionare a soli due cilindri, consentendo un risparmio di 0,4 litri ogni 100 km. Quando il sistema è abbinato allo Start&Stop, la diminuzione della richiesta di carburante raggiunge gli 0,6 litri per 100 km.

Col piede leggero si viaggia a due. All'atto pratico, viaggiando a 50 km/h in terza o quarta marcia, si può risparmiare - secondo i dati rilasciati dalla Casa - fino a un litro ogni 100 chilometri. La disattivazione di due dei quattro cilindri del 1.4 TSI è attiva tra i 1.400 e i 4.000 giri al minuto quando la coppia motrice è compresa tra i 25 e 75 Newtonmetri: queste condizioni si verificano per il 70% della percorrenza nel ciclo di guida europeo standard.

Condizionato dallo stile di guida. Il passaggio da due a quattro cilindri è istantaneo e impercettibile e il funzionamento a due cilindri, inoltre, non compromette il confort di marcia. Il sistema, che rileva le informazioni di guida dal sensore di posizione del pedale dell'acceleratore, viene disattivato automaticamente quando lo stile di guida non è costante oppure sportivo.

Passato e presente. Ricordiamo che un sistema di disattivazione dei cilindri è stato recentemente introdotto dalla Mercedes, sul V8 aspirato di 5.5 litri che equipaggia la SLK 55 AMG, e dall'Audi sul V8 di 4.0 litri biturbo delle nuove S6, S7 Sportback e S8. In passato, precisamente negli anni Ottanta, analoghe sperimentazioni in piccola serie erano state effettuate dalla Cadillac e dall'Alfa Romeo. C.D.G.

[TonyH]

Volevate la C a 2 cilindri, eccovela qua

Mò voglio vedere cosa si troverà per giustificare una premium-Golf che vi passerà accanto in modalità "risparmiosa-scorreggiante"

Spero che abbiano messo contralberi di equilibratura, sennò te lo raccomando quando gira a due

[Guest EC2277]

Non credo che servano: la combustione in un cilindro avviene ogni 2 giri e la pressione massima si raggiunge con la biella quasi verticale. Per questo si tende a non considerare gli effetti della combustione quando si fa il bilanciamento delle forze alterne.

Ci si concentra solo su quelle d'inerzia pertanto, passando da 4 a 2 cilindri attivi, non si avvertiranno grosse differenze.

Semmai il motore potrebbe sembrare più irregolare ma credo che il volano sia sufficiente a regolarizzare la coppia motrice.