Volkswagen Touareg Hybrid Concept (Foto Ufficiali)

[j]

Volkswagen Touareg V6 TSI Hybrid Concept

In parallel to pure gasoline and diesel versions, Volkswagen will be bringing the next version of the Touareg to market as a hybrid version too. Average fuel consumption: less than 9.0 liters fuel per 100 kilometers. CO2 emissions: less than 210 g/km. For the first time, there is now a near-production prototype that offers initial glimpses of the full hybrid technology that will be implemented on the future Touareg. This experimental platform has its conceptual basis in the current generation of the SUV. The car’s powertrain already embodies many aspects of the future Touareg Hybrid. It will be powered by a new V6 TSI – a highly advanced gasoline direct injection engine boosted by a mechanically-driven supercharger – in tandem with an electric motor. It will have a newly developed 8-speed automatic transmission. Volkswagen will be implementing a parallel hybrid drive on the future Touareg V6 TSI Hybrid. This version of the SUV will have a high-performance, full-time all-wheel drive too.

V6 TSI stands for maximum power with minimum consumption

The V6 TSI on the Touareg prototype is fun to drive and delivers 245 kW / 333 PS at 5,500 rpm. From its 2,995 cm3 displacement, it generates a maximum torque of 440 Newton-meters starting from 3,000 rpm. These characteristics match those of the Touareg with an eight cylinder engine, yet with the V6 TSI it is significantly more fuel efficient. This represents the principle of intelligent downsizing (less displacement plus gasoline direct injection plus inlet boosting) already established by Volkswagen on the globally successful TSI four cylinder engines, and it is now being applied to six-cylinder engines. The results are convincing. The substantial torque delivery that came from using a supercharger becomes even more fascinating with the addition of the E-motor, especially at low speeds. If required, an exceptional amount of torque is available from a standstill – a bonus that comes from a system that is designed for efficiency. To increase further this efficiency, the V6 TSI makes use of a switchable engine water pump. This remains off during the warm-up phase, ensuring rapid achievement of fuel efficient operation.. The pump is integrated into the vehicle’s overall heat management system.

V6 TSI plus E-motor drives fuel consumption below 9.0 liters

The E-motor integrated between the V6 TSI and the 8-speed automatic transmission adds power of 38 kW / 52 PS and up to 300 Newton-meters torque. In so-called boosting – where requests for maximum power and torque (by kickdown or gearshift selector in “S” position) are supported by the engagement of both V6 TSI and electric drive systems – the powertrain briefly supplies a power of 275 kW / 374 PS and the maximum available torque increases to 550 Newton-meters. In this case, the Touareg V6 TSI Hybrid prototype accelerates to 100 km/h in just 6.8 seconds.

The hybrid system of the Touareg was not designed to deliver sports car performance. Its purpose is to deliver very low emissions and fuel consumption values. It may therefore come as a surprise to learn that this exceptional performance is accompanied by an average fuel consumption of less than 9.0 liters per 100 kilometers. CO2 emissions are less than 210 g/km. The Touareg V6 TSI Hybrid will attain the limits of the Euro-5 and American ULEV2 emissions standards.

More than 25 percent better fuel economy

Compared to a conventional SUV of the same size, the hybrid concept yields fuel savings of more than 25 percent in city driving. Development engineers calculate an average savings of 17 percent in combined city, highway and freeway driving. Essentially, there are four parameters with which the Volkswagen prototype achieves this improved fuel economy.

Start-stop system: an integrated start-stop system significantly reduces fuel consumption, especially in urban driving.

Regenerative braking: during braking, the E-motor operates as a generator and recovers energy, which is then stored in the high voltage battery (NiMH batteries). This means that the E-motor recovers a proportion of the energy that would otherwise be rejected in the form of heat through the braking system. It comes into effect progressively during the initial travel of the brake pedal.

The E-motor: The vehicle can operate on the electric motor alone at speeds of up to 50 km/h, which reduces fuel consumption in city driving. In this case the V6 TSI is turned off, and it is disconnected from the transmission by a disengagement clutch. In this condition the Touareg V6 TSI Hybrid operates with zero emissions. Electric current flows from the battery to the E-motor via the power electronics which incorporates a pulse controlled inverter. On the later production version, there are also plans for a special E-switch that the driver can activate for pure electric driving.

Coasting: as soon as the driver removes his or her foot from the gas pedal, a clutch disengages the V6 TSI from the transmission. This is even possible at higher speeds – in the later production version up to about 160 km/h – and therefore in freeway driving as well. This eliminates mechanical drag losses, which in turn makes the Touareg coast significantly better. The driver can convert this directly into improved fuel economy by adopting an anticipatory driving style.

Intelligent energy mix

With regard to powertrain types – and their associated energy flows – besides electric driving and coasting there are two other operating modes: classic driving with internal combustion engine and the boosting that is typical of hybrid vehicles.

When driving with just the internal combustion engine, there are two possible modes of operation. In the first case, the Touareg is driven like a conventional vehicle with the E-motor performing the function of a conventional 12 V alternator, which it replaces, to supply sufficient energy for the vehicle’s electrical system and maintain battery charge (in this case a high voltage battery). In the second case, the engine supplies the energy needed to propel the vehicle plus the energy needed to charge the high voltage battery via the E-motor, but at a higher rate, replacing energy taken from battery when in conditions when the E-motor has been operating as an electric motor. This so-called load point shifting makes it possible to operate the engine at a more favorable level of efficiency in the engine load/speed map. The job of hybrid control is now to regulate this alternation of electric driving phases and active charge phases to achieve minimal fuel consumption.

Boosting: when the driver consciously activates a request for maximum power (kickdown or gearshift lever in “S” position), the E-motor supports the V6 TSI beyond the engine’s full-load curve. The powers and torques of these two motors are then transferred to the front and rear axles by the 8-speed automatic transmission. As previously mentioned, this briefly makes available a total combined power of up to 275 kW / 374 PS and a maximum torque of 550 Newton-meters.

In addition, since it can be controlled extremely quickly the E-motor is also used – in the framework of so-called transient compensation – to make positive and negative torque interventions. For example, when the driver makes a positive load request the E-motor briefly boosts the V6 TSI until it has reached its steady-state target value. This allows the Touareg Hybrid to keep accelerating. Negative torque interventions largely replace classic interventions via the internal combustion engine that are not optimal for efficiency, but are needed for occupant comfort during gear shifting or sudden charge changes.

The specific mode that is activated is shown by an energy flow indicator in the display of the RNS 510 radio-navigation system installed in the prototype vehicle.

Basic technical layout of the hybrid drive

Volkswagen has chosen a parallel hybrid drive for use in the Touareg. In contrast to other possible hybrid systems, both off-road properties and unlimited continuous climbing capabilities are assured. With a maximum trailer load of up to 3.5 metric tons, the Touareg V6 TSI Hybrid can also be recommended as an ideal towing vehicle. Furthermore, the parallel hybrid approach offers a higher level of efficiency than alterne hybrid concepts in cross-country and freeway driving.

The powertrain itself primarily consists of the V6 TSI, the 8-speed automatic transmission that is also ideally suited for hybrid and tow vehicle use and the hybrid module integrated between the internal combustion engine and the automatic transmission. The latter weighs 55 kilograms. The compact module houses – in one unit – the disengagement clutch located after the V6 engine and the E-motor.

The interplay of components is “directed” by a hybrid manager. This multi-functional unit is integrated in the engine controller and communicates via the CAN bus lines with units such as the automatic transmission, high voltage battery and so-called power electronics that controls the electric motor. The latter also manages the energy flow between the electric motor and battery. Using the DC/DC converter, the power electronics also ensures that the car’s 12V electrical system is supplied via the E-motor or the high voltage battery. Depending on the charge state of the battery (capacity: 6 Ah), vehicle speed and other vehicle-specific parameters, the hybrid manager automatically selects the ideal operating mode based on lightning fast analysis of all signals.

Nickel metal hydride battery in detail

The nickel metal-hydride battery used in the Touareg V6 TSI Hybrid reflects what is currently the best and most practical electric storage system for automobiles. Functional safety, robustness and cost are all factors that favor the high-performance NiMH battery.

The battery is located in a space saving area. On the prototype the cargo floor has been raised by 50 millimeters. The battery weighs 67 kilograms, consists of a total of 240 individual cells and therefore generates a voltage of 288 Volt. An additional duct integrated in the Touareg’s interior ventilation system and two separate fans are used to keep the battery within an optimal temperature range. A battery manager continually monitors battery charge by coordinating data with the hybrid manager integrated in the engine controller.

Special power cables connect the battery to the power electronics – located to the left of the engine in the front of the vehicle – to supply the E-motor with energy or – in the reverse case – to charge the battery by E-motor while it acts as a generator when braking (regenerative braking) or by the V6 TSI (via load point shift). In the event of a crash, the high voltage battery is protected by what is known as a “Protect Box”. The battery system, which includes the Protect Box, battery and ventilation components, weighs 79 kilograms.

Partial compensation for added weight of hybrid system

To compensate for a portion of the weight of the hybrid components (about 175 kilograms), the prototype exhibits numerous modifications compared to the production vehicle. One example is the full-time 4XMotion all-wheel drive. In today’s Touareg, the drive is transferred to the front and rear axles via a transfer box which contains a lockable central differential and a two-speed range gearbox. On the Touareg V6 TSI Hybrid this is replaced by a lighter Torsen differential similar to the one Audi uses on the Q7. All the traditional capabilities of the Touareg are fully preserved, such as its optimal properties as a towing vehicle.

Other changes compared to the production Touareg

Various components have been redeveloped to retain all the traditional convenience and safety-related functions of the standard Touareg in the Touareg V6 TSI Hybrid. For example, the prototype has electro-hydraulic power steering, which does not have to rely on a servo pump driven by the internal combustion engine. In addition, a high voltage air conditioning compressor guarantees comfortable interior temperatures on the Touareg V6 TSI Hybrid, even when the V6 engine is switched off. Instead of an alternator, the DC/DC converter integrated in the power electronics ensures a constant supply of power to the vehicle electrical system.

The 8-speed automatic transmission was also specifically tuned for hybrid use. Among other things, it received a special torque converter with larger lock-up system, an auxiliary electric oil pump (to maintain a supply of oil when the V6 TSI is switched off), a transmission heater to reach optimal operating temperature faster, and a modified transmission controller.

Car is started by electric motor

The E-motor now takes over the role of engine starter motor. This job is especially challenging, since restarting of the V6 TSI must be executed with a high degree of smoothness and precision to maintain comfortable transitions between the various modes of propulsion. As soon as the engine is to be restarted, the transmission’s lock-up torque converter is put in the “Slip” position and the E-motor’s speed is increased to a setpoint value prescribed by the transmission controller. Only then does the engine controller receive an enable to actuate the disengagement clutch. The E-motor “drags up” the V6 TSI by subsequent engagement of the clutch and, as soon as the cylinders fill, the engine is started by enabling of injection and ignition. The E-motor’s torque is increased by the amount of the momentary torque transferred by the disengagement clutch during the drag operation and – after the internal combustion engine has started – it is reduced again in response to the increase in engine torque. When positive engagement occurs at the disengagement clutch, the lock-up torque converter is engaged again. All of this sounds complicated, and it is complicated, but the system operates in such a way that the driver and occupants are completely unaware of its contribution to smooth progress. And that is just how things should be.

da Km77.com & theCarfanatic.com

Modificato 2 Febbraio 2009 da j

[j]

Volkswagen Touareg V6 TSI Hybrid: presto sul mercato

Nuovo motore a benzina 3 litri con unità elettrica

La Volkswagen Touareg sarà sul mercato con una nuova versione ibrida, in grado di offrire un nuovo set di contenuti tecnologici e innovativi nell’ambito della gamma. Il modello più virtuoso della famiglia farà parte delle novità del restyling che dovrebbe fare il suo ingresso ufficiale sul mercato nel 2010.

Il primo apporto al movimento sarà fornito da un’unità a 6 cilindri a V del tipo “TSI”, ovvero con iniezione diretta di benzina e turbocompressore a geometria variabile. Con una cilindrata di 2.995 cc, sprigiona 333 CV a 5.500 giri e 440 Nm di coppia massima a partire da 3.000 giri. La seconda unità motrice sarà un motore elettrico. Il peso complessivo di tutti i componenti è nell’ordine di 175 chili, comprendendo modulo elettrico vero e proprio e gruppo batterie al NiMh. Denominato E-motor e sistemato tra il V6 e il cambio, è in grado di fornire 52 CV di potenza e un valore di coppia fino a 300 Nm.

La Touareg ibrida funziona con il solo motore elettrico fino a una velocità di 50 km/h. A velocità superiori entra in gioco il benzina, che nelle occasioni in cui è richiesta particolare potenza, riceve l’ausilio dell’unità elettrica (per esempio durante una fase di kickdown o quando il cambio opera in modalità sportiva). Con il funzionamento combinato di entrambi i motori, infatti, la Touareg TSI Hybrid eroga, complessivamente 374 CV e ha il suo picco di forza motrice in 550 Nm. Dal punto di vista prestazionale, questo si tradurrà in uno scatto da 0 a 100 che la Casa dichiara essere di soli 6”8, un dato interessante a dispetto di un peso consistente.

L’elettronica di bordo gestisce al meglio l’intervento del motore elettrico in chiave di massima efficienza energetica ma anche di comfort di guida. Avvia l’auto e, gradatamente, lascia impercettibilmente il posto al motore a combustione che inizia a fornire coppia, lo assiste brevemente nelle fasi di accelerazione, si ricarica nelle fasi di frenata, fornisce coppia aggiuntiva quando richiesto per ottimizzare al meglio il funzionamento del 6 cilindri o, come accennato, per fornire maggiore spunto in accelerazione e ripresa particolarmente intensa.

Ovviamente la vettura offrirà trazione integrale permanente 4Motion del tipo evoluto; quello della Touareg Hybrid è simile a quello dell’Audi Q7, con due differenziali sugli assi e un differenziale centrale tipo Torsen. La trasmissione si completa con un inedito cambio automatico a 8 rapporti.

Nonostante i valori di performance siano elevati, la Touareg TSI Hybrid non è stata pensata per offrire il meglio soprattutto nel comparto prestazioni. La sua missione è quella di proporre al mercato un’auto con consumi contenuti e basse emissioni di sostanze nocive. La casa dichiara per il modello definitivo un consumo medio pari a 9 litri di benzina ogni 100 chilometri e un valore di emissione medio pari a 210 g/km di Co2. Rispetto a un veicolo di pari categoria ma non equipaggiato con unità ibrida, Volkswagen calcola che quest’auto offre un risparmio del 25% di consumo nella guida su “circuito” urbano e il 17% su strada extraurbana e autostrada.

Autore: Alvise-Marco Seno

[Guest Linda]

Farà la fine della Golf ibrida?

(presentata per Ginevra 2008, spentita ad aprile)

[GTI 150 97]

Dedicata a chi non vuole fumare

[itr83]

motore endotermico da 333 cv su 2500 kg di Suv e dovrebbe fare 11 km/l ??

ma in quale universo??

[Regazzoni]

motore endotermico da 333 cv su 2500 kg di Suv e dovrebbe fare 11 km/l ??

ma in quale universo??

[itr83]

Plausibile, sulla carta, ma poi spiego il perchè e il come.

Rincaro prima la dose sui dubbi sui numeri di questo concept.

Un motore elettrico da 52 CV che dovrebbe portare in giro da solo un mezzo da 2,5 tonnellate (vuoto) fino ai 50 km/h?

Ma nemmeno in "zona 30" si muoverebbe decentemente in quelle condizioni.

Giusto le (non)accelerazioni del ciclo ECE urbano di rilevamento dei consumi può fornire.

E qui torniamo al dato sul consumo: gran parte di quei 9 litri/100 km derivano dal consumo (secondo ciclo omologativo) urbano.

E siccome nel ciclo omologativo (non proprio realistico rispetto al reale uso di un mezzo del genere) il motore elettrico ce la fa anche da solo, ecco che i consumi rilevati diventano molto facilmente (e molto artificialmente) più bassi.

[j]

Volkswagen Touareg Hybrid

What is it?

This is the Volkswagen Touareg hybrid. It’s Volkswagen’s first real go at petrol-electric hybrid drive, although it will a while before you can buy a Touareg hybrid. This drivetrain - a 323bhp petrol V6 from Audi and an eight-speed automatic - won’t feature in the current Touareg, but will be launched in the next-generation model, due in 2010.

In the VW Touareg hybrid there’s a 38kw (51bhp) motor powered by a nickel-metal hydride battery pack mounted underneath the boot in the space usually reserved for the spare tyre.

The layout of the VW Touareg hybrid, known as a parallel system, is familiar, having already appeared in a number of hybrids. But by employing a disengagement clutch, the VW Touareg hybrid has overcome one major drawback, namely that the petrol engine and electric motor are always connected.

In some hybrids the crankshaft and pistons within the petrol engine continue to operate even during electric-only propulsion. This adds to wear and also zaps overall efficiency.

The VW Touareg hybrid uses the disengagement clutch to ensure the petrol engine is shut down completely when the electric engine is in use.

What’s it like?

The VW Touareg hybrid’s electric motor is terrifically refined, providing almost seamless operation in the city, with impressive levels of performance and the sort of fuel economy to make diesel lovers turn green with envy. Still, it does take some getting used to before you feel totally comfortable behind the wheel.

When you crank the key, the petrol engine doesn’t fire up unless the batteries are low on energy or, as we discovered on occasion in a freezing Wolfsburg, it is extremely cold. Instead, the Touareg hybrid wafts away solely on electric power.

The electric motor is powerful enough to provide the sole mode of propulsion for the Touareg hybrid up to 30mph. Yet when the engine kicks in the changeover is barely perceptible.

It’s quick too - 62mph comes in a claimed in 6.8sec, 0.7sec faster than the 4.2-litre V8 Touareg.

More impressive are the increases in economy and consequent reduction in emissions. Combined economy is 31.4mpg, 3mpg better than the V6 diesel Touareg, while the CO2 rating is 210g/km.

The hybrid drive system adds around 175kg to the kerb weight of the Touareg, so there’s a new, lighter four-wheel drive system which replaces the multi-plate clutch with a version of Audi’s Torsen differential.

Other drawbacks? By employing a disengagement clutch, The VW Touareg hybrid is to use its petrol engine to charge the batteries while the car is running on electric power.

Should I buy one?

There’s no doubt that hybrid drive greatly extends the appeal of the Touareg, providing it with performance and green credentials, so it’s a shame that you won’t be able to get the VW Touareg hybrid until the second-generation model arrives in 2010.

Still, that at least gives VW’s engineers time to further improve what is already one of the most effective combinations of petrol and electric propulsion yet devised.

da AutoCar.co.uk