On Comman Rail Direct Injection Essay Sample
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Diesel fuel injector as installed in a MAN V8 Diesel engine
Common rail direct fuel injection is a modern discrepancy of direct fuel injection system for gasoline and Diesel engines. On Diesel engines. it features a high-pressure ( over 1. 000 saloon or 15. 000 pounds per square inch ) fuel rail feeding single solenoid valves. as opposed to low-pressure fuel pump feeding unit injectors ( Pumpe/Duse or pump noses ) . Third-generation common rail Diesels now feature piezoelectric injectors for increased preciseness. with fuel force per unit areas up to 1. 800 saloon or 26. 000 pounds per square inch. In gasolene engines. it is used in gasolene direct injectionengine engineering. ————————————————-
The common rail system paradigm was developed in the late sixtiess by Robert Huber of Switzerland and the engineering further developed by Dr. Marco Ganser at theSwiss Federal Institute of Technology in Zurich. later of Ganser-Hydromag AG ( est. 1995 ) in Oberageri. The first successful use in a production vehicle began inJapan by the mid-1990s. Dr. Shohei Itoh and Masahiko Miyaki of the Denso Corporation. a Nipponese automotive parts maker. developed the common rail fuel system for heavy responsibility vehicles and turned it into practical usage on their ECD-U2 common-rail system mounted on the Hino Rising Ranger truck and sold for general usage in 1995. [ 1 ] Denso claims the first commercial high force per unit area common rail system in 1995. [ 2 ] Modern common rail systems. whilst working on the same rule. are governed by an engine control unit ( ECU ) which opens each injector electronically instead than automatically. This was extensively prototyped in the 1990s with coaction between Magneti Marelli. Centro Ricerche Fiat and Elasis. After research and development by the Fiat Group. the design was acquired by the German companyRobert Bosch GmbH for completion of development and polish for mass-production. In hindsight. the sale appeared to be a tactical mistake for Fiat. as the new engineering proved to be extremely profitable.
The company had small pick but to sell. nevertheless. as it was in a hapless fiscal province at the clip and lacked the resources to finish development on its ain. [ 3 ] In 1997 they extended its usage for rider autos. The first rider auto that used the common rail system was the 1997 theoretical account Alfa Romeo 156 2. 4 JTD. [ 4 ] and subsequently on that same twelvemonth Mercedes-Benz C 220 CDI. Common rail engines have been used in Marine and locomotor applications for some clip. The Cooper-Bessemer GN-8 ( circa 1942 ) is an illustration of a hydraulicly operated common rail Diesel engine. besides known as a modified common rail. Vickers used common rail systems in undersea engines circa 1916. Doxford Engines Ltd. [ 5 ] ( opposed-piston heavy Marine engines ) used a common rail system ( from 1921 to 1980 ) whereby a multi-cylinder reciprocating fuel pump generated a force per unit area of about 600 saloon. with the fuel being stored in collector bottles.
Pressure control was achieved by agencies of an adjustable pump discharge shot and a “spill valve” . Camshaft-operated mechanical timing valves were used to provide the spring-loaded Brice/CAV/Lucas injectors. which injected through the side of the cylinder into the chamber formed between the Pistons. Early engines had a brace of clocking Cams. one for in front running and one for astern. Later engines had two injectors per cylinder. and the concluding series of constant-pressure turbocharged engines were fitted with four injectors per cylinder. This system was used for the injection of both diesel oil and heavy fuel oil ( 600cSt heated to a temperature of about 130 °C ) . The common rail system is suited for all types of route autos with diesel engines. runing from metropolis autos such as the Fiat Nuova Panda to executive autos such as the Audi A6. ————————————————-
[ edit ] Common rail today
Robert Bosch GmbH. Delphi Automotive Systems. Denso Corporation. and Siemens VDO ( now owned by Continental AG ) are the chief providers of modern common rail systems. The auto shapers refer to their common rail engines by their ain trade name names: * Ashok Leyland’s CRS Engines ( used in U Truck and E4 Busses ) * BMW’s D-engines ( besides used in the Land RoverFreelander TD4 ) * Chevrolet’s VCDi ( licensed from VM Motori )
* Cummins and Scania’s XPI ( Developed under joint venture ) * Cummins CCR ( Cummins pump with Bosch Injectors )
* Daimler’s CDI ( and on Chrysler’s Jeep vehicles merely as CRD ) * Fiat
Group’s ( Fiat. Alfa Romeo and Lancia ) JTD ( besides branded as MultiJet. JTDm. Ecotec CDTi. TiD. TTiD. DDiS. Quadra-Jet ) * Ford Motor Company’s TDCi Duratorq and Powerstroke
* Honda’s i-CTDi & A ; i-DTEC
* Hyundai & A ; Kia’s CRDi
* IKCO’s EFD which is one of the members of the EF household. Supplier TBD * Isuzu’s iTEQ
* Komatsu’s Tier3. Tier4. 4D95 and higher – HPCR series Diesel engines. * Mahindra’s CRDe
* Mazda’s MZR-CD & A ; Skyactiv-D ( 1. 4 MZ-CD. 1. 6 MZ-CD manufactured by joint venture Ford/PSA Peugeot Citroen ) and earlier DiTD * Mitsubishi’s DI-D ( late developed 4N1 engine household uses following coevals 200 MPa ( 2000 saloon ) injection system ) ) * Nissan’s Director of Central Intelligence. Infiniti uses dCi engines. but non branded as Director of Central Intelligence. * Opel’s CDTI
* Proton’s SCDi
* PSA Peugeot Citroen’s HDI or HDi ( 1. 4HDI. 1. 6 HDI. 2. 0 HDI. 2. 2 HDI and V6 HDI developed under joint venture with Ford ) * Renault’s Director of Central Intelligence ( joint venture with Nissan )
* SsangYong’s XDi ( most of these engines are manufactured by Daimler AG ) * Subaru’s Legacy TD ( as of Jan 2008 )
* Tata’s DICOR & A ; CR4
* Toyota’s D-4D & A ; D-Cat
* Volkswagen Group: The 6. 0 V12 TDI. 4. 2 TDI ( V8 ) . 2. 7 and 3. 0 TDI ( V6 ) . 1. 6. 2. 0 TDI ( L4 ) and 1. 2 TDI ( L3 ) engines featured on current Seat. Skoda. VW and Audi theoretical accounts use common rail. as opposed to the earlier unit injector engines. * Volvo 2. 4D and D5 engines ( 1. 6D. 2. 0D manufactured by Ford and PSA Peugeot Citroen ) . Volvo Penta D-serie engines * Wartsila-Sulzer 14RT-flex96-C “largest reciprocating engine in the world” designed by the Finnishmanufacturer Wartsila ————————————————-
[ edit ] Principles
Solenoid or piezoelectric valves make possible all right electronic control over the fuel injection clip and measure. and the higher force per unit area that the common rail engineering makes available provides better fuel atomization. In order to lower engine noise. the engine’s electronic control unit can shoot a little sum of Diesel merely before the chief injection event ( “pilot” injection ) . therefore cut downing its explosiveness and quiver. every bit good as optimizing injection timing and measure for fluctuations in fuel quality. cold starting and so on. Some advanced common rail fuel systems perform every bit many as five injections per shot. [ 6 ] Common rail engines require really short ( & lt ; 10 second ) or no heating-up clip at all [ commendation needed ] . dependant on ambient temperature. and bring forth lower engine noise and emanations than older systems. Diesel engines have historically used assorted signifiers of fuel injection. Two common types include the unit injection system and the distributor/inline pump systems ( See diesel engine and unit injector for more information ) . While these older systems provided accurate fuel measure and injection timing control. they were limited by several factors: *
They were cam driven. and injection force per unit area was relative to engine velocity. This typically meant that the highest injection force per unit area could merely be achieved at the highest engine velocity and the maximal accomplishable injection force per unit area decreased as engine velocity decreased. This relationship is true with all pumps. even those used on common rail systems ; with the unit or distributer systems. nevertheless. the injection force per unit area is tied to the instantaneous force per unit area of a individual pumping event with no collector. and therefore the relationship is more outstanding and troublesome. * They were limited in the figure and timing of injection events that could be commanded during a individual burning event. While multiple injection events are possible with these older systems. it is much more hard and dearly-won to accomplish. * For the typical distributor/inline system. the start of injection occurred at a pre-determined force per unit area ( frequently referred to as: dad force per unit area ) and ended at a pre-determined force per unit area. This characteristic resulted from “dummy” injectors in the cylinder caput which opened and closed at force per unit areas determined by the spring preload applied to the speculator in the injector.
Once the force per unit area in the injector reached a pre-determined degree. the speculator would raise and injection would get down. In common rail systems. a hard-hitting pump shops a reservoir of fuel at high force per unit area — up to and above 2. 000 bars ( 29. 000 pounds per square inch ) . The term “common rail” refers to the fact that all of the fuel injectors are supplied by a common fuel rail which is nil more than a force per unit area collector where the fuel is stored at high force per unit area. This collector supplies multiple fuel injectors with hard-hitting fuel. This simplifies the intent of the hard-hitting pump in that it merely has to keep a commanded force per unit area at a mark ( either automatically or electronically controlled ) . The fuel injectors are typically ECU-controlled.
When the fuel injectors are electrically activated. a hydraulic valve ( dwelling of a nose and speculator ) is automatically or hydraulicly opened and fuel is sprayed into the cylinders at the coveted force per unit area. Since the fuel force per unit area energy is stored remotely and the injectors are electrically actuated. the injection force per unit area at the start and terminal of injection is really near the force per unit area in the collector ( rail ) . therefore bring forthing a square injection rate. If the collector. pump and plumbing are sized decently. the injection force per unit area and rate will be the same for each of the multiple injection events.