Misplaced Pages

#156843

53-476: A unit injector ( UI ) is a high-pressure integrated direct fuel injection system for diesel engines , combining the injector nozzle and the injection pump in a single component. The plunger pump used is usually driven by a shared camshaft . In a unit injector, the device is typically lubricated and cooled by the fuel itself. High-pressure injection delivers power and fuel consumption benefits over earlier lower-pressure fuel injection by injecting fuel as

106-405: A hot-bulb engine used a 'jerk pump' to dispense fuel oil at high pressure to an injector. Another development in early diesel engines was the pre-combustion chamber, which was invented in 1919 by Prosper l'Orange to avoid the drawbacks of air-blast injection systems. The pre-combustion chamber made it feasible to produce engines in size suitable for automobiles and MAN Truck & Bus presented

159-610: A spark plug . The Cummins Model H diesel truck engine was introduced in America in 1933. In 1936, the Mercedes-Benz OM 138 diesel engine (using a precombustion chamber) became one of the first fuel-injected engines used in a mass-production passenger car. During World War II , several petrol engines for aircraft used direct-injection systems, such as the European Junkers Jumo 210 , Daimler-Benz DB 601 , BMW 801 , and

212-451: A carburettor. Many of the carburettor's supporting components—such as the air filter, intake manifold, and fuel line routing—could be used with few or no changes. This postponed the redesign and tooling costs of these components. Single-point injection was used extensively on American-made passenger cars and light trucks during 1980–1995, and in some European cars in the early and mid-1990s. In the US,

265-581: A central injector instead of multiple injectors. Single-point injection (also called 'throttle-body injection') uses one injector in a throttle body mounted similarly to a carburettor on an intake manifold . As in a carburetted induction system, the fuel is mixed with the air before entering the intake manifold. Single-point injection was a relatively low-cost way for automakers to reduce exhaust emissions to comply with tightening regulations while providing better "driveability" (easy starting, smooth running, no engine stuttering) than could be obtained with

318-667: A common-rail design, such as the new 1.6 TDI. In North America , the Volkswagen Jetta , Golf , and New Beetle TDI 2004–2006 are Pumpe Düse (available in both the MK4 and MK5 generations, with BEW and BRM engine codes respectively, older models use timing belt-driven injection pump). TDI engines incorporating PD unit injector systems manufactured by the Volkswagen Group were also installed on some cars sold in Europe and other markets where

371-572: A fuel injection system are described in the following sections. In some systems, a single component performs multiple functions. Fuel injection is operated by spraying pressurised fuel into the engine. Therefore a device to pressurise the fuel is needed, such as a fuel pump. The system must determine the appropriate amount of fuel to be supplied and control the fuel flow to supply this amount. Several early mechanical injection systems used relatively sophisticated helix-controlled injection pump(s) that both metered fuel and created injection pressure. Since

424-705: A fuel injection system in 1941 and by 1956 it was used in the Jaguar racing cars. At the 1957 24 Hours of Le Mans , the 1st to 4th placed cars were Jaguar D-Type entries using a Lucas fuel injection system. Also in 1957, General Motors introduced the Rochester Ramjet option, consisting of a fuel injection system for the V8 engine in the Chevrolet Corvette. During the 1960s, fuel injection systems were also produced by Hilborn , SPICA and Kugelfischer . Up until this time,

477-509: A larger number of smaller droplets, giving a much higher ratio of surface area to volume. This provides improved vaporisation from the surface of the fuel droplets and so more efficient combining of atmospheric oxygen with vaporised fuel, delivering more complete and cleaner combustion. In 1911, a patent was issued in Great Britain for a unit injector resembling those in use today to Frederick Lamplough . Commercial usage of unit injectors in

530-573: A passenger car was released the following year, in the Mercedes-Benz 300SL sports car. However the engine suffered lubrication problems due to petrol diluting the engine oil, and subsequent Mercedes-Benz engines switched to a manifold injection design. Likewise, most petrol injection systems prior to the 2000s used the less-expensive manifold injection design. Throughout the 1950s, several manufacturers introduced their manifold injection systems for petrol engines. Lucas Industries had begun developing

583-477: A pulsed flow system which used an air flow meter to calculate the amount of fuel required. L-Jetronic was widely adopted on European cars during the 1970s and 1980s. As a system that uses electronically-controlled fuel injectors which open and close to control the amount of fuel entering the engine, the L-Jetronic system uses the same basic principles as modern electronic fuel injection (EFI) systems. Prior to 1979,

SECTION 10

#1733094010157

636-399: A sophisticated common-rail injection system. The latter is the most common system in modern automotive engines. During the 20th century, most petrol engines used either a carburettor or indirect fuel injection. Use of direct injection in petrol engines has become increasingly common in the 21st century. In a common rail system, fuel from the fuel tank is supplied to a common header (called

689-579: A vehicle may be considered a commercial vehicle if it: A vehicle can be used for a business, if not exclusively, and remain privately licensed, depending on the amount of time used for business. In the United States, the Federal Motor Carrier Safety Administration defines a "commercial motor vehicle" as any self-propelled or towed vehicle used on a public highway in interstate commerce to transport passengers or property when

742-594: A wide variety of vehicles and engines; commercial vehicles from manufacturers such as Volvo , Cummins , Detroit Diesel , CAT , Navistar International and passenger vehicles from manufacturers such as Land Rover and Volkswagen Group , among others, and locomotives from Electromotive Diesel . The Volkswagen Group mainstream marques used unit injector systems (branded ”Pumpe Düse” , commonly abbreviated to ”PD” ) in their Suction Diesel Injection (SDI) and Turbocharged Direct Injection (TDI) diesel engines , however this fuel injection method has been superseded by

795-501: Is a broad definition, as commercial vehicles may be fleet vehicles , company cars , or other vehicles used for business. Vehicles that are designed to carry more than 15 passengers are considered a commercial vehicle. Variations may exist from state-to-state on which "commercial vehicles" are prohibited on certain routes and lanes and between homeowner associations, which may employ broader definitions than their municipalities with regard to their own parking restrictions. Broadly defined,

848-413: Is always intermittent (either sequential or cylinder-individual). This can be done either with a blast of air or hydraulically, with the latter method being more common in automotive engines. Typically, hydraulic direct injection systems spray fuel into the air inside the cylinder or combustion chamber. Direct injection can be achieved with a conventional helix-controlled injection pump, unit injectors, or

901-546: Is called a manifold injection system. There exist two types of manifold injection systems: multi-point injection (or port injection) and single-point injection (or throttle body injection). Internal mixture formation systems can be separated into several different varieties of direct and indirect injection, the most common being the common-rail injection system, a variety of direct injection. The term "electronic fuel injection" refers to any fuel injection system controlled by an engine control unit . The fundamental functions of

954-533: Is injected at the same time to all the cylinders; or cylinder-individual , in which the engine control unit can adjust the injection for each cylinder individually. Multi-point injection (also called 'port injection') injects fuel into the intake ports just upstream of each cylinder's intake valve , rather than at a central point within an intake manifold. Typically, multi-point injected systems use multiple fuel injectors, but some systems, such as GM's central port injection system, use tubes with poppet valves fed by

1007-415: The Mercedes-Benz OM 138 ) became available in the late 1930s and early 1940s, being the first fuel-injected engines for passenger car use. In passenger car petrol engines, fuel injection was introduced in the early 1950s and gradually gained prevalence until it had largely replaced carburetors by the early 1990s. The primary difference between carburetion and fuel injection is that fuel injection atomizes

1060-548: The Shvetsov ASh-82FN (M-82FN) . The German direct-injection systems were based on diesel injection systems used by Bosch, Deckel, Junkers and l'Orange. By around 1943, the Rolls-Royce Merlin and Wright R-3350 had switched from traditional carburettors to fuel-injection (called "pressure carburettors" at the time), however these engines used throttle body manifold injection , rather than the direct-injection systems of

1113-521: The U.S. began in early 1930s on Winton engines powering locomotives, boats, even US Navy submarines, and in 1934, Arthur Fielden was granted U.S. patent No.1,981,913 on the unit injector design later used for the General Motors two-stroke diesel engines . Most mid-sized diesel engines used a single pump and separate injectors, but some makers, such as Detroit Diesel and Electro-Motive Diesel became well known for favouring unit injectors, in which

SECTION 20

#1733094010157

1166-460: The Volkswagen 1.4 FSI engine introduced in 2000. However, the stratified charge systems were largely no longer in use by the late 2010s, due to increased exhaust emissions of NOx gasses and particulates, along with the increased cost and complexity of the systems. Commercial vehicles In the United States, a vehicle is designated "commercial" when it is titled or registered to a company. This

1219-475: The Wankel engine . In a manifold injection system, air and fuel are mixed outside the combustion chamber so that a mixture of air and fuel is sucked into the engine. The main types of manifold injections systems are multi-point injection and single-point injection . These systems use either a continuous injection or an intermittent injection design. In a continuous injection system, fuel flows at all times from

1272-669: The accumulator ), and then sent through tubing to the injectors, which inject it into the combustion chamber. The accumulator has a high-pressure relief valve to maintain pressure and return the excess fuel to the fuel tank. The fuel is sprayed with the help of a nozzle that is opened and closed with a solenoid-operated needle valve . Third-generation common rail diesels use piezoelectric injectors for increased precision, with fuel pressures up to 300  MPa or 44,000  psi . The types of common-rail systems include air-guided injection and spray-guided injection . Used by diesel engines, these systems include: This injection method

1325-709: The filling phase , the spill phase , the injection phase , and the pressure reduction phase . A low-pressure fuel delivery pump supplies filtered diesel fuel into the cylinder head fuel ducts, and into each injector fuel port of constant stroke pump plunger injector, which is overhead camshaft operated. The use of electronic control allows for special functions; such as temperature controlled injection timing, cylinder balancing (smooth idle), switching off individual cylinders under part load for further reduction in emissions and fuel consumption, and multi-pulse injection (more than one injection occurrence during one engine cycle). Unit injector fuel systems are being used on

1378-437: The throttle body . Fuel injectors which also control the metering are called "injection valves", while injectors that perform all three functions are called unit injectors . Direct injection means that the fuel is injected into the main combustion chamber of each cylinder. The air and fuel are mixed only inside the combustion chamber. Therefore, only air is sucked into the engine during the intake stroke. The injection scheme

1431-549: The 1950 Goliath GP700 small saloon, it was also added to the Gutbrod Superior engine in 1952. This mechanically-controlled system was essentially a specially lubricated high-pressure diesel direct-injection pump of the type that is governed by the vacuum behind an intake throttle valve. A Bosch mechanical direct-injection system was also used in the straight-eight used in the 1954 Mercedes-Benz W196 Formula One racing car. The first four-stroke direct-injection petrol engine for

1484-428: The 1954-1959 Mercedes-Benz 300 SL - all used manifold injection (i.e. the injectors located at the intake ports or throttle body, instead of inside the combustion chamber). This began to change when the first mass-produced petrol direct injection system for passenger cars was a common rail system introduced in the 1997 Mitsubishi 6G74 V6 engine. The first common-rail system for a passenger car diesel engine

1537-452: The 1980s, electronic systems have been used to control the metering of fuel. More recent systems use an electronic engine control unit which meters the fuel, controls the ignition timing and controls various other engine functions. The fuel injector is effectively a spray nozzle that performs the final stage in the delivery of fuel into the engine. The injector is located in the combustion chamber , inlet manifold or - less commonly -

1590-571: The Electrojector system, becoming the first cars known to use an electronic fuel injection (EFI) system. The Electrojector patents were subsequently sold to Bosch, who developed the Electrojector into the Bosch D-Jetronic . The D-Jetronic was produced from 1967-1976 and first used on the VW 1600TL/E . The system was a speed/density system, using engine speed and intake manifold air density to calculate

1643-497: The G10 engine in the 2000 Chevrolet Metro became the last engine available on an American-sold vehicle to use throttle body injection. In indirect-injected diesel engines (as well as Akroyd engines), there are two combustion chambers: the main combustion chamber, and a pre-chamber (also called an ante-chamber) that is connected to the main one. The fuel is injected only into the pre-chamber (where it begins to combust), and not directly into

Unit injector - Misplaced Pages Continue

1696-600: The German engines. From 1940, the Mitsubishi Kinsei 60 series engine used a direct-injection system, along with the related Mitsubishi Kasei engine from 1941. In 1943, a low-pressure fuel injection system was added to the Nakajima Homare Model 23 radial engine. The first mass-produced petrol direct-injection system was developed by Bosch and initially used in small automotive two-stroke petrol engines. Introduced in

1749-567: The HEUI system for multiple engines including the DT 466E , DT 570, T-444E , DT-466–570, MaxxForce 5, 7, 9, 10, MaxxForce DT and VT365 engines. Caterpillar incorporated HEUI systems in the 3116, 3126, C7, C9 among others and the Daimler-Detroit Diesel Series 40 engine supplied by International also incorporated a HEUI fuel system. Isuzu fitted a HEUI system to their 3.0 LTR 4JX1 engine fitted to

1802-798: The Trooper and its variants. The HEUI system has been replaced by many manufacturers with common rail injection solutions, a newer technology, to meet better fuel economy and new emissions standards being introduced. Fuel injection Fuel injection is the introduction of fuel in an internal combustion engine , most commonly automotive engines , by the means of a fuel injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All compression-ignition engines (e.g. diesel engines ), and many spark-ignition engines (i.e. petrol (gasoline) engines , such as Otto or Wankel ), use fuel injection of one kind or another. Mass-produced diesel engines for passenger cars (such as

1855-571: The amount of fuel to be injected. In 1974, Bosch introduced the K-Jetronic system, which used a continuous flow of fuel from the injectors (rather than the pulsed flow of the D-Jetronic system). K-Jetronic was a mechanical injection system, using a plunger actuated by the intake manifold pressure which then controlled the fuel flow to the injectors. Also in 1974, Bosch introduced the L-Jetronic system,

1908-408: The cylinder head. Each injector has its own pumping element, and in the case of electronic control, a fuel solenoid valve as well. The fuel system is divided into the low-pressure (<500  kPa ) fuel supply system, and the high-pressure injection system (<2000  bar ). Technical characteristics: Advantages: The basic operation can be described as a sequence of four separate phases:

1961-564: The diesel engine, but also improved it. He increased the air blast pressure from 4–5 kp/cm (390–490 kPa) to 65 kp/cm (6,400 kPa). In the meantime, the first manifold injection system was designed by Johannes Spiel in 1884, while working at Hallesche Maschinenfabrik in Germany. In 1891, the British Herbert-Akroyd oil engine became the first engine to use a pressurised fuel injection system. This design, called

2014-642: The diesel fuel was conveniently priced, amongst those there were some Chrysler/Dodge cars of the DaimlerChrysler era, e.g. the Dodge Calibre (MY07 BKD, MY08 BMR), Dodge Journey , Jeep Compass , Jeep Patriot . Volkswagen Group major-interest truck and diesel engine maker Scania AB also uses the unit injector system, which they call “ Pumpe-Düse-Einspritzung ”, or ”PDE” . In 1993, CAT and International Truck & Engine Corporation introduced "hydraulically actuated electronic unit injection” (HEUI), where

2067-411: The electronics in fuel injection systems used analogue electronics for the control system. The Bosch Motronic multi-point fuel injection system (also amongst the first systems where the ignition system is controlled by the same device as the fuel injection system) was the first mass-produced system to use digital electronics . The Ford EEC-III single-point fuel injection system, introduced in 1980,

2120-441: The first direct-injected diesel engine for trucks in 1924. Higher pressure diesel injection pumps were introduced by Bosch in 1927. In 1898, German company Deutz AG started producing four-stroke petrol stationary engines with manifold injection. The 1906 Antoinette 8V aircraft engine (the world's first V8 engine) was another early four-stroke engine that used manifold injection. The first petrol engine with direct-injection

2173-631: The fuel injection systems had used a mechanical control system. In 1957, the American Bendix Electrojector system was introduced, which used analogue electronics for the control system. The Electrojector was intended to be available for the Rambler Rebel mid-size car, however reliability problems meant that the fuel injection option was not offered. In 1958, the Chrysler 300D , DeSoto Adventurer , Dodge D-500 and Plymouth Fury offered

Unit injector - Misplaced Pages Continue

2226-572: The fuel injectors, but at a variable flow rate. The most common automotive continuous injection system is the Bosch K-Jetronic system, introduced in 1974 and used until the mid-1990s by various car manufacturers. Intermittent injection systems can be sequential , in which injection is timed to coincide with each cylinder's intake stroke; batched , in which fuel is injected to the cylinders in groups, without precise synchronization to any particular cylinder's intake stroke; simultaneous , in which fuel

2279-633: The fuel through a small nozzle under high pressure, while carburetion relies on suction created by intake air accelerated through a Venturi tube to draw fuel into the airstream. The term "fuel injection" is vague and comprises various distinct systems with fundamentally different functional principles. Typically, the only thing all fuel injection systems have in common is a lack of carburetion . There are two main functional principles of mixture formation systems for internal combustion engines: internal mixture formation and external mixture formation. A fuel injection system that uses external mixture formation

2332-406: The high-pressure pump is contained within the injector itself. E.W. Kettering's 1951 ASME presentation goes into detail about the development of the modern Unit injector. Also Cummins PT (pressure-time) is a form of unit injection where the fuel injectors are on a common rail fed by a low-pressure pump and the injectors are actuated by a third lobe on the camshaft. The pressure determines how much fuel

2385-494: The injectors are no longer camshaft -operated and could pressurise fuel independently of engine RPM. First available on Navistar's 7.3L /444 cuin , V8 diesel engine . HEUI uses engine oil pressure to power high-pressure fuel injection, where the usual method of unit injector operation is with the engine camshaft. HEUI applications included the Ford 7.3L and 6.0L Power stroke used between May 1993 and 2007. International also used

2438-524: The injectors get and the time is determined by the cam. In 1994, Robert Bosch GmbH supplied the first electronic unit injector for commercial vehicles, and other manufacturers soon followed. In 1995, Electromotive Diesel converted its 710 diesel engines to electronic fuel injection, using an EUI which replaces the UI. Today, major manufacturers include Robert Bosch GmbH , CAT , Cummins , ⁣ Delphi , ⁣ Detroit Diesel , Electro-Motive Diesel . The design of

2491-503: The main combustion chamber. Therefore, this principle is called indirect injection. There exist several slightly different indirect injection systems that have similar characteristics. Types of indirect injection used by diesel engines include: In 1872, George Bailey Brayton obtained a patent on an internal combustion engine that used a pneumatic fuel injection system, also invented by Brayton: air-blast injection . In 1894, Rudolf Diesel copied Brayton's air-blast injection system for

2544-421: The unit injector eliminates the need for high-pressure fuel pipes, and with that, their associated failures, as well as allowing for much higher injection pressure to occur. The unit injector system allows accurate injection timing, and amount of control as in the common rail system . The unit injector is fitted into the engine cylinder head , where the fuel is supplied via integral ducts machined directly into

2597-400: The vehicle: The federal definition, though followed closely, is meant to accommodate and remain flexible to each state's definitions. The European Union defines a "commercial motor vehicle" as any motorized road vehicle, that by its type of construction and equipment is designed for, and capable of transporting, whether for payment or not: Commercial trucks are classified according to

2650-424: Was a two-stroke aircraft engine designed by Otto Mader in 1916. Another early spark-ignition engine to use direct-injection was the 1925 Hesselman engine , designed by Swedish engineer Jonas Hesselman. This engine could run on a variety of fuels (such as oil, kerosene, petrol or diesel oil) and used a stratified charge principle whereby fuel is injected towards the end of the compression stroke, then ignited with

2703-407: Was another early digital fuel injection system. These and other electronic manifold injection systems (using either port injection or throttle-body injection ) became more widespread through the 1980s, and by the early 1990s they had replaced carburettors in most new petrol-engined cars sold in developed countries. The aforementioned injection systems for petrol passenger car engines - except for

SECTION 50

#1733094010157

2756-449: Was previously used in many diesel engines. Types of systems include: The M-System , used in some diesel engines from the 1960s to the 1980s, sprayed the fuel onto the walls of the combustion chamber, as opposed to most other direct-injection systems which spray the fuel into the middle of the chamber. Manifold injection systems are common in petrol-fuelled engines such as the Otto engine and

2809-466: Was the Fiat Multijet straight-four engine, introduced in the 1999 Alfa Romeo 156 1.9 JTD model. Since the 2010s, many petrol engines have switched to direct-injection (sometimes in combination with separate manifold injectors for each cylinder). Similarly, many modern diesel engines use a common-rail design. Stratified charge injection was used in several petrol engines in the early 2000s, such as

#156843