MACHINE INJECTION

MACHINE INJECTION
(01/03/2006) - Mercedes-Benz unveiled the 2007 CLS 350 CGI engine technology Stratified-Charged Gasoline Injection which is claimed as the first vehicle to offer a petrol engine with piezoelectric direct injection and spray-guided combustion. This technology increases engine output while improving fuel consumption bahar.

The major advantage of the CGI engine is stratified as the operation name. In this condition, the machine works with high air concentrations, but can be efiesiensi high fuel. And the recent achievement of this technology enables operation pattern poor fuel combustion (lean-burn) occurs at high rpm and heavy loads. Fuel consumption CLS 350 CGI to 9.1 liters per 100km.

The way this technology works when simplified is as follows: Each Langkap compression, occurred a series of fuel spray with a gap of a split second. Thus a process of continuous refinement mixed gasoline / air combustion and fuel efficiency.

First, stratified operation is only possible at low workload, but now Mercedes direct-injection engine is still operating at a speed of more than 120km/jam. On the freeway where the car is moving with constant velocity, the CGI engine can save 15% than other six-cylinder engine.
The idea of ​​spraying fuel into the combustion chamber and then mixes with the air, about 70 years old in the minds of Mercedes engineers. When was the first to adopt this concept is aircraft engine Mercedes (DB601) with direct petrol injection. In April 1939, a Messerschmidt M 209 with DB 601 series engines are air-kW/2768 2035 hp output speed achieved 755.1 km / h, the new world record broken 30 years later. On land, direct injection engine menunai sensation in the era of the 50's through a series of victories by the 300 SLR Gullwing 300 SL phenomenon in 1954. M198 six-cylinder engine produces a top speed 260km/jam 158kW/215hp.

Piezoelectric pulses

The development of direct-injection entering new territory when the 1994 Mercedes began developing spray-guided combustion process is considered as a response to the two challenges of today's automotive fuel consumption is lower and the reduction of toxic emissions. Advantages directional spray (spray-guided) versus direct injection was significantly increased thermodynamic efficiency. In the spray-guided, fuel is sprayed with high precision, by the time the car needs, diaman gasoline can be burned almost entirely by the amount of air very much.

However, applications in mass production hindered injection technology, in particular valve petrol injection with spray can flat / uniform and stable in all operating conditions in place adjacent to the spark plugs. Until 1994, Mercedes-Benz engineers began working on piezoelectric technology, which consists of a special ceramic material and metal alloys. Privileges are piezoelectric material that can change shape / pulsating with millisecond speed if given an electric twitch. Piezo vibration is directly translated as an injector needle movement that determines the flow through the valve. This produces a smooth motion, constant and can produce spray patterns identical every time.

Piezoelectric-bukaanya that gap just a few microns, can produce hollow funnel-shaped spray pattern of the uniform. This system is keeping the spraying like that though engine management system, change the angle of the intake camshafts. Fuel pressure reached 200bar also contribute to the stability of the consistency of the fuel spray. In a matter of microseconds, piezoelectric spray when doing repeated for each step and the compression and lean-burn operation.

To ensure spark plugs can jump quickly at any time, the spark plug should be able to reach the clouds mixture of fuel / air but should not be in direct contact with the liquid fuel because it can cause carbonation. The solution, piezo-injectors CGI engine is stuck to the center of the combustion chamber, close to the position of the spark plug. Busi also repositioned near the valve out, where she could reach the mixed fuel / air turbulence at the end of the funnel-shaped spray of gasoline. Coolant flowing in the cylinder head ensure plugs and injectors operate at temperatures finest.

Requirements to improve the working piezoelectric injection technology is stratified very quickly. Every step of compression, piezoelectric spray several times and further improve the composition of the mixture and the ease to burn. Combustion occurs more quickly, evenly and thoroughly than with just one spray. In addition, the thermodynamic efficiency of the engine increases significantly and hydrocarbon emissions cut by more than half.




Mercedes designed the piston head with a specially designed niche where konsentarasi lean mixture (lean mixtures) were around the spark plug and prevent it spreading through the cylinder wall.

Similar comon-rail diesel

The fuel injection system on the new V6 engine is similar to the modern diesel engine with common-rail technology. They both use a high-pressure pump that distributes fuel through stainless steel rails on the cylinder as needed. Piezoelectric injector connected to these rails.



With pressures up to 200bar, the new system increases the fuel pressure up to 50 times compared to conventional injection systems. Pump sends fuel to the rail each spraying. Regulating valve to make sure the amount of fuel needed at a particular operating point can be delivered on the dose. It helps relieve the high pressure pump working. Unneeded fuel is sent back through the water heat exchanger (cooling water) and mixed back with fresh fuel from the tank CLS 350 CGI. This coolant also cools the direct injection engine electronic controls.

Another Innovation

Besides pioneer in the injection process, a number of technological innovations are also offered in this V6 engine. Variable camshaft timing on the intake and exhaust manifold which regulates opening and closing of the valves at the most suitable according to the needs.

Variable intake air supply modules are arranged as needed with elongated / cut the flow of air through the manifold. The result Tosi and 87% maximum 317Nm of torque is available from 1500rpm.

Improved fuel economy with the thermal management system. The circulation of heated air when the engine is stopped, so that the engine can reach operating temperature more quickly. In working conditions, thermal management system keeping the oil temperature and coolant temperature best. Work may take place due to the electronic controlled thermostat.

Cranckcase of the cylinder head and aluminum. Pistons, connecting rods and cylincer liner is designed with the latest principles, in addition to light but also contribute to the smooth movement of all components.