Innovation is a choice and a challenge. It is the area in which Aprilia tests itself against the current competition. To predict trends. To satisfy both reason and emotion. To interpret the needs of man in the era of technology.
In 1992, Aprilia was the first company to launch onto the market a two-stroke
scooter with a catalytic converter. In 1993, the company began developing
the first scooter with a four stroke four valve engine:
ecology and performance were finally combined into the one vehicle.
The DITECH is an innovative engine using electronic direct injection,
employing of the ultimate in
A huge leap forward in terms of performance, reduction in fuel consumption and pollution; without losing sight of the main aims: simplicity, reliability, safety, character, power and above all the thrill of riding.
This is technology at its most flexible, applicable to almost the entire range of Aprilia scooters, offering great scope for development. Which means that it is capable of responding with flexibility to possible future limitations in terms of approval, without having recourse to a catalyzer or other additional elements.
THE ADVANTAGES OF APRILIA DITECH
Reduction in the consumption of fuel
Improvements in performance and reliability
Polluting emissions reduced
Longer working life and greater reliability
with electronic control.
The DITECH engine is completely under the control of an electronic control unit. This unit enables a continuous self-diagnosis to be carried out on all the components of the system and signals in real time to the rider any possible malfunctionings that may occur.
In a traditional two-stroke engine, the chamber is scavenged with the mixture. A considerable quantity of unburned fuel and oil therefore enters the exhaust directly and is discharged into the environment (greater pollution and higher consumption). In the DITECH system, the chamber is scavenged only with air. The mixture therefore enters only when the exhaust ports are closed.
DITECH uses sophisticated electronic pumps to meter the petrol and oil. All the functional phases of the engine are controlled by sensors, which constantly send information back to the electronic control unit. Thanks to a continuous self-diagnosis of the system, the electronic control unit regulates the functioning of the engine and optimises it.
ELEMENTS OF THE APRILIA DITECH SYSTEM
ELECTRONIC PETROL PUMP Takes the petrol from the tank to the air-fuel rail. This is not a traditional pump, however, but rather an innovative pump that functions under high pressure (approximately 6 Bar). Despite the high level of performance, the pump uses a very low amount of electrical energy, particularly when compared to a traditional pump.
AIR-FUEL RAIL This element is
made up of three distinct components:
Direct Injector: This is perhaps the fundamental element in the system. The role of the Direct Injector, which is electronically controlled by the electronic control unit, is to mix the petrol coming from the Fuel Injector with the compressed air, employing of the pressure of the latter (5 Bar) to inject it directly into the combustion chamber. The more the petrol/air mixture is finely nebulised and the charge well stratified, the more the yield from the system improves. In order to get an idea of the precision required of this component, one should bear in mind that an automobile injection system nebulises with particles that are 50 microns in size (SMD measurement, Sauter average diameter) and a direct-injection diesel engine reaches dimensions of 25-30 microns. The Aprilia DITECH system allows for a nebulisation with drops of 8 microns, which have an evaporation time that is less than one millisecond.
Pressure regulator: The Fuel Injector functions thanks to a pressure differential between the petrol and the circuit of compressed air. The regulator guarantees that the pressure remains stable, ensuring precise opening times for the Fuel Injector valve that injects the required amounts.
COMPRESSOR The 5-Bar compressor sends the compressed air to the Direct Injector. The intervention of the compressor serves to atomise the charge; in contrast, in an automobile engine, the compressor serves to supercharge the engine itself. The compressor is controlled by an eccentric on the crank of the drive shaft. This technical solution has allowed the designers to avoid using an external compressor, which would have involved the use of additional tubes, autonomous lubrication circuits and suction of filtered air. These latter elements would have represented a complicated and considerably more expensive alternative.
ELECTRONIC OIL PUMP The oil pump is a solenoid pump, which is electronically activated in order to ensure maximum precision in its functioning. The DITECH system guarantees that only the right quantity of oil is supplied in order to lubricate the engine. This quantity is calculated on the basis of information received/processed by the electronic control unit.
IGNITION/COIL The DITECH engine requires a powerful, precise and reliable ignition. Only by means of such an ignition can it ensure complete combustion, engine efficiency and the elimination of unburned hydrocarbons in the exhaust gas.
ELECTRONIC CONTROL UNIT (ECU) - The heart
of the system, this is an extremely compact
BUTTERFLY VALVE In the DITECH engine, the traditional throttle body, which regulates the suction of the air (controlled by the throttle cable), has an added feature. The valve is fitted with an electronic sensor entitled TPS (Throttle Position Sensor), which reads the throttle opening and transmits the information to the electronic control unit.