1.Direct fuel injection technology for petrol engines GDI (Gasoline Direct Injection).
The idea of direct fuel injection on the petrol engine is Swedish engineer: Jonas Hesselman first applied to the hybrid "Hesselman engine" - A combination of gasoline engine and diesel engine in 1925, then this engine fitted on aircraft to use during World War 2 . Next, Bosch developed this engine for two carmakers are Goliath and Gutbrod and released in 1953. This technology is still pursued by car manufacturers but no major breakthrough in the popularity of the car market.
n 1996, Mitsubishi suddenly brought this technology back to the consumer on the Galant cars and auto manufacturers introduce this technology on one or several of its models such as Nissan Car Leopard (1997), Toyota D4 engine with the SZ and NZ (1998) or Renault Megane form of (1999) ...
The biggest difference of gasoline direct injection technology compare with the engine electronic fuel injection is due to placed nozzle in front xupap and formation of a mixture of gasoline and air outside the combustion chamber , directly fuel injection system is placed nozzle directly inside the cylinder nozzle so the mixture of fuel and air will be formed directly in the combustion chamber.
Injection process is divided into two phases.During loading, a small amount of fuel is injected prior to the combustion chamber to cooling load, which increases the amount of gas loaded into the cylinder. The main injection process takes place when the piston reaches top dead center of the compression stroke just before the ignition spark.
with the characteristics works like diesel so the top of the piston structure of the GDI engine is also designed like the diesel engine to make sure the fuel and the air brought into the cylinder, mixing a darkpros and evenly across the space of the combustion chamber. Besides, the fuel injector on GDI engines also have larger injection pressure helps fuel particles are ejected to. This explains why the GDI engine can operate with very dilute mixture in light load conditions and engine work at high speed at the same time to raise the engine's compression ratio to 12.5 : one that did not occur to detonate while the conventional gasoline engine compression ratio only at 9-10,5:1.
In addition to using the GDI gasoline direct injection technology, engine of Q3 were mixture with increased pressure Turbochager help increase engine power, a 15% reduction in fuel consumption and cleaner emissions compared withelectronic fuel injection engine. Because the material used as piston and cylinder must be durable (due to the heat generated in the combustion is much higher), and made more complex nozzle also increases costs, so this is an important reason for directly fuel injection system GDI not as popular as electronic fuel injection EFI.
2 .7-speed dual-clutch gearbox S-tronic
Theoretically, the gearbox as many levels as convenient for users because it can satisfy various working conditions of load and road surface. However they have the disadvantage is the time when shifting. Imagine walking along the highway to 7 ie driving lever 7 times - too inconvenient to use. And dual-clutch gearbox is the solution can solve the two problems.
S-tronic called "hybrid transmission" because it combines the advantages of the gearbox and automatic transmission. On this box instead of using the dry friction clutch on the conventional mechanical gearbox that uses friction plates clutch with hydraulic torque converter automatic gearbox as the shift becomes smooth process softer. However, this is not an automatic transmission because S-tronic uses pairs of gear fits in addition to not using planetary gear transmission, gear pairs associated with two independent axes from the friction disc transmission can make seven different - something that conventional mechanical gearbox or automatic transmission does not meet due to the inconvenience when want to transfer.
Terms of structure, S-Tronic using 2 sets of friction discs operate independently to lead for interlocking two axes and on the shaft driven gear fitted to the hand. 2nd axis external placed the gears driving the No. 2,4,6, while the shaft 1 (nested axis 2) arrangement of gears driving the odd 1.3, 7, 5 . Thus, when vehicle is operating at 1 can be readily transferred to No. 3 without to go through 2, so driver can switch from No. 1 to No. 7 just over 3 times transfer - this makes driving convenient and time saving to.
In addition, S-Tronic gearbox fitted on Q3 has a new improved, when car is moving but the sensor identified no impact on gas pedal or brake pedal immediately friction plates will be extracted, this time car will move completely rely on inertia without traction engine - act as a drag due engine work at low rpm. So engine will save fuel.
(.. be continue)
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