109-433: The Mercedes-Benz Econic is a low-entry truck introduced by Mercedes-Benz in 1998. It is available in weights of 18 t and 26 t and is powered by a six-cylinder inline engine with turbo and intercooler. It is normally used for waste collection , fire and emergency purposes and airport ground services. In 2014, it received a facelift which included new headlamps and a revised front grille. This truck-related article
218-414: A carcinogen or "probable carcinogen" and is known to increase the risk of heart and respiratory diseases. In principle, a diesel engine does not require any sort of electrical system. However, most modern diesel engines are equipped with an electrical fuel pump, and an electronic engine control unit. However, there is no high-voltage electrical ignition system present in a diesel engine. This eliminates
327-406: A fifth wheel hitch. Box trucks have walls and a roof, making an enclosed load space. The rear has doors for unloading; a side door is sometimes fitted. Chassis cab trucks have a fully enclosed cab at the front, with bare chassis frame-rails behind, suitable for subsequent permanent attachment of a specialized payload, like a fire-truck or ambulance body. Concrete mixers have
436-485: A 25 mph (40 km/h) speed governor as they are classified as low-speed vehicles. These vehicles have found uses in construction, large campuses (government, university, and industrial), agriculture, cattle ranches, amusement parks, and replacements for golf carts. Major mini-truck manufacturers and their brands include: Daihatsu Hijet , Honda Acty , Tata Ace , Mazda Scrum , Mitsubishi Minicab , Subaru Sambar , and Suzuki Carry . Light trucks are car-sized (in
545-401: A common construction: they are made of a chassis , a cab , an area for placing cargo or equipment, axles , suspension and roadwheels , an engine and a drivetrain . Pneumatic , hydraulic , water , and electrical systems may also be present. Many also tow one or more trailers or semi-trailers. The "cab", or "cabin" is an enclosed space where the driver is seated. A " sleeper " is
654-711: A compartment attached to or integral with the cab where the driver can rest while not driving, sometimes seen in semi-trailer trucks. There are several cab configurations: A further step from this is the side loading forklift that can be described as a specially fabricated vehicle with the same properties as a truck of this type, in addition to the ability to pick up its own load. Most small trucks such as sport utility vehicles (SUVs), vans or pickups , and even light medium-duty trucks in North America, China, and Russia use gasoline engines (petrol engines), but many diesel engined models are now being produced. Most of
763-452: A diesel engine drops at lower loads, however, it does not drop quite as fast as the Otto (spark ignition) engine's. Diesel engines are combustion engines and, therefore, emit combustion products in their exhaust gas . Due to incomplete combustion, diesel engine exhaust gases include carbon monoxide , hydrocarbons , particulate matter , and nitrogen oxides pollutants. About 90 per cent of
872-580: A factory to the nearest railway station. The first semi-trailer appeared in 1881, towed by a steam tractor manufactured by De Dion-Bouton . Steam-powered wagons were sold in France and the United States until the eve of World War I , and 1935 in the United Kingdom, when a change in road tax rules made them uneconomic against the new diesel lorries. In 1895, Karl Benz designed and built
981-516: A few degrees releasing the pressure and is controlled by a mechanical governor, consisting of weights rotating at engine speed constrained by springs and a lever. The injectors are held open by the fuel pressure. On high-speed engines the plunger pumps are together in one unit. The length of fuel lines from the pump to each injector is normally the same for each cylinder in order to obtain the same pressure delay. Direct injected diesel engines usually use orifice-type fuel injectors. Electronic control of
1090-407: A finite area, and the net output of work during a cycle is positive. The fuel efficiency of diesel engines is better than most other types of combustion engines, due to their high compression ratio, high air–fuel equivalence ratio (λ) , and the lack of intake air restrictions (i.e. throttle valves). Theoretically, the highest possible efficiency for a diesel engine is 75%. However, in practice
1199-452: A fuel consumption of 519 g·kW ·h . However, despite proving the concept, the engine caused problems, and Diesel could not achieve any substantial progress. Therefore, Krupp considered rescinding the contract they had made with Diesel. Diesel was forced to improve the design of his engine and rushed to construct a third prototype engine. Between 8 November and 20 December 1895, the second prototype had successfully covered over 111 hours on
SECTION 10
#17328016219341308-409: A full set of valves, two-stroke diesel engines have simple intake ports, and exhaust ports (or exhaust valves). When the piston approaches bottom dead centre, both the intake and the exhaust ports are "open", which means that there is atmospheric pressure inside the cylinder. Therefore, some sort of pump is required to blow the air into the cylinder and the combustion gasses into the exhaust. This process
1417-562: A heterogeneous air-fuel mixture. The torque a diesel engine produces is controlled by manipulating the air-fuel ratio (λ) ; instead of throttling the intake air, the diesel engine relies on altering the amount of fuel that is injected, and thus the air-fuel ratio is usually high. The diesel engine has the highest thermal efficiency (see engine efficiency ) of any practical internal or external combustion engine due to its very high expansion ratio and inherent lean burn, which enables heat dissipation by excess air. A small efficiency loss
1526-406: A ladder if tipped on end. The rails consist of a tall vertical section (two if boxed) and two shorter horizontal flanges. The height of the vertical section provides opposition to vertical flex when weight is applied to the top of the frame (beam resistance). Though typically flat the whole length on heavy-duty trucks, the rails may sometimes be tapered or arched for clearance around the engine or over
1635-403: A low-pressure loop at the bottom of the diagram. At 1 it is assumed that the exhaust and induction strokes have been completed, and the cylinder is again filled with air. The piston-cylinder system absorbs energy between 1 and 2 – this is the work needed to compress the air in the cylinder, and is provided by mechanical kinetic energy stored in the flywheel of the engine. Work output is done by
1744-420: A manual transmission with synchromesh (synchronizers). Bigger trucks often use manual transmissions without synchronizers, saving bulk and weight, although synchromesh transmissions are used in larger trucks as well. Transmissions without synchronizers, known as "crash boxes", require double-clutching for each shift, (which can lead to repetitive motion injuries), or a technique known colloquially as "floating",
1853-545: A manual transmission, while conventional automatic or automated manual transmissions would have anything from 5 to 12 gears. Almost all heavy truck transmissions are of the "range and split" (double H shift pattern) type, where range change and so‑called half gears or splits are air operated and always preselected before the main gear selection. A truck frame consists of two parallel boxed (tubular) or C‑shaped rails, or beams, held together by crossmembers . These frames are referred to as ladder frames due to their resemblance to
1962-407: A method of changing gears which does not use the clutch, except for starts and stops, due to the physical effort of double-clutching, especially with non-power-assisted clutches, faster shifts, and less clutch wear. Double-clutching allows the driver to control the engine and transmission revolutions to synchronize so that a smooth shift can be made; for example, when upshifting, the accelerator pedal
2071-532: A more efficient replacement for stationary steam engines . Since the 1910s, they have been used in submarines and ships. Use in locomotives , buses, trucks, heavy equipment , agricultural equipment and electricity generation plants followed later. In the 1930s, they slowly began to be used in some automobiles . Since the 1970s energy crisis , demand for higher fuel efficiency has resulted in most major automakers, at some point, offering diesel-powered models, even in very small cars. According to Konrad Reif (2012),
2180-510: A more uncertain origin, but probably has its roots in the rail transport industry, where the word is known to have been used in 1838 to refer to a type of truck (a goods wagon as in British usage, not a bogie as in the American), specifically a large flat wagon. It might derive from the verb lurry (to carry or drag along, or to lug) which was in use as early as 1664, but that association
2289-681: A notable exception being the EMD 567 , 645 , and 710 engines, which are all two-stroke. The power output of medium-speed diesel engines can be as high as 21,870 kW, with the effective efficiency being around 47-48% (1982). Most larger medium-speed engines are started with compressed air direct on pistons, using an air distributor, as opposed to a pneumatic starting motor acting on the flywheel, which tends to be used for smaller engines. Medium-speed engines intended for marine applications are usually used to power ( ro-ro ) ferries, passenger ships or small freight ships. Using medium-speed engines reduces
SECTION 20
#17328016219342398-535: A petroleum engine with glow-tube ignition in the early 1890s; he claimed against his own better judgement that his glow-tube ignition engine worked the same way Diesel's engine did. His claims were unfounded and he lost a patent lawsuit against Diesel. Other engines, such as the Akroyd engine and the Brayton engine , also use an operating cycle that is different from the diesel engine cycle. Friedrich Sass says that
2507-415: A poorer power-to-mass ratio than an equivalent petrol engine. The lower engine speeds (RPM) of typical diesel engines results in a lower power output. Also, the mass of a diesel engine is typically higher, since the higher operating pressure inside the combustion chamber increases the internal forces, which requires stronger (and therefore heavier) parts to withstand these forces. The distinctive noise of
2616-408: A regular trunk-piston. Two-stroke engines have a limited rotational frequency and their charge exchange is more difficult, which means that they are usually bigger than four-stroke engines and used to directly power a ship's propeller. Four-stroke engines on ships are usually used to power an electric generator. An electric motor powers the propeller. Both types are usually very undersquare , meaning
2725-401: A roof and floor, used for transporting fresh and frozen cargo such as ice cream, food, vegetables, and prescription drugs. They are mostly equipped with double-wing rear doors, but a side door is sometimes fitted. Refuse trucks have a specialized body for collecting and, often, compacting trash collected from municipal, commercial, and industrial sites. This application has the widest use of
2834-547: A rotating drum on an inclined axis, rotating in one direction to mix, and in the other to discharge the concrete down chutes. Because of the weight and power requirements of the drum body and rough construction sites, mixers have to be very heavy duty. Dual drive/Steer trucks are vehicles used to steer the rear of trailers . Dump trucks ("tippers" in the UK) transport loose material such as sand, gravel, or dirt for construction. A typical dump truck has an open-box bed, which
2943-435: A simple mechanical injection system since exact injection timing is not as critical. Most modern automotive engines are DI which have the benefits of greater efficiency and easier starting; however, IDI engines can still be found in the many ATV and small diesel applications. Indirect injected diesel engines use pintle-type fuel injectors. Early diesel engines injected fuel with the assistance of compressed air, which atomised
3052-536: A single orifice injector. The pre-chamber has the disadvantage of lowering efficiency due to increased heat loss to the engine's cooling system, restricting the combustion burn, thus reducing the efficiency by 5–10%. IDI engines are also more difficult to start and usually require the use of glow plugs. IDI engines may be cheaper to build but generally require a higher compression ratio than the DI counterpart. IDI also makes it easier to produce smooth, quieter running engines with
3161-527: A single speed for long periods. Two-stroke engines use a combustion cycle which is completed in two strokes instead of four strokes. Filling the cylinder with air and compressing it takes place in one stroke, and the power and exhaust strokes are combined. The compression in a two-stroke diesel engine is similar to the compression that takes place in a four-stroke diesel engine: As the piston passes through bottom centre and starts upward, compression commences, culminating in fuel injection and ignition. Instead of
3270-709: A six-axle truck may have a maximum weight of 44 t (97,000 lb) or more. Off-road trucks include standard, extra heavy-duty highway-legal trucks, typically outfitted with off-road features such as a front driving axle and special tires for applications such as logging and construction, and purpose-built off-road vehicles unconstrained by weight limits, such as the Liebherr T 282B mining truck. Australia has complex regulations over weight and length, including axle spacing, type of axle/axle group, rear overhang, kingpin to rear of trailer, drawbar length, ground clearance, as well as height and width laws. These limits are some of
3379-426: A small chamber called a swirl chamber, precombustion chamber, pre chamber or ante-chamber, which is connected to the cylinder by a narrow air passage. Generally the goal of the pre chamber is to create increased turbulence for better air / fuel mixing. This system also allows for a smoother, quieter running engine, and because fuel mixing is assisted by turbulence, injector pressures can be lower. Most IDI systems use
Mercedes-Benz Econic - Misplaced Pages Continue
3488-530: A source of radio frequency emissions (which can interfere with navigation and communication equipment), which is why only diesel-powered vehicles are allowed in some parts of the American National Radio Quiet Zone . To control the torque output at any given time (i.e. when the driver of a car adjusts the accelerator pedal ), a governor adjusts the amount of fuel injected into the engine. Mechanical governors have been used in
3597-400: A spark plug ( compression ignition rather than spark ignition ). In the diesel engine, only air is initially introduced into the combustion chamber. The air is then compressed with a compression ratio typically between 15:1 and 23:1. This high compression causes the temperature of the air to rise. At about the top of the compression stroke, fuel is injected directly into the compressed air in
3706-417: A swirl chamber or pre-chamber are called indirect injection (IDI) engines. Most direct injection diesel engines have a combustion cup in the top of the piston where the fuel is sprayed. Many different methods of injection can be used. Usually, an engine with helix-controlled mechanic direct injection has either an inline or a distributor injection pump. For each engine cylinder, the corresponding plunger in
3815-411: A truck, of a trailer, from axle to hitch point, kingpin to rear of trailer, and turning radius are all regulated. In additions, there are special rules for carrying containers, and countries can set their own rules for local traffic. The United States Federal Bridge Law deals with the relation between the gross weight of the truck, the number of axles, the weight on and the spacing between the axles that
3924-422: A two-stroke ship diesel engine has a single-stage turbocharger with a turbine that has an axial inflow and a radial outflow. In general, there are three types of scavenging possible: Crossflow scavenging is incomplete and limits the stroke, yet some manufacturers used it. Reverse flow scavenging is a very simple way of scavenging, and it was popular amongst manufacturers until the early 1980s. Uniflow scavenging
4033-622: A version of their Xebra electric tricycle (licensable in the U.S. as a motorcycle). Popular in Europe and Asia, many mini-trucks are factory redesigns of light automobiles, usually with monocoque bodies. Specialized designs with substantial frames such as the Italian Piaggio shown here are based upon Japanese designs (in this case by Daihatsu ) and are popular for use in "old town" sections of European cities that often have very narrow alleyways. Regardless of name, these small trucks serve
4142-573: A wide range of uses. In Japan, they are regulated under the Kei car laws, which allow vehicle owners a break in taxes for buying a smaller and less-powerful vehicle (currently, the engine is limited to 660 cc displacement). These vehicles are used as on-road utility vehicles in Japan. These Japanese-made mini-trucks that were manufactured for on-road use are competing with off-road ATVs in the United States, and import regulations require that these mini-trucks have
4251-592: Is a stub . You can help Misplaced Pages by expanding it . Truck A truck or lorry is a motor vehicle designed to transport freight , carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction, with a cabin that is independent of the payload portion of the vehicle. Smaller varieties may be mechanically similar to some automobiles . Commercial trucks can be very large and powerful and may be configured to be mounted with specialized equipment, such as in
4360-461: Is a combustion engine that is more efficient than a diesel engine, but due to its mass and dimensions, is unsuitable for many vehicles, including watercraft and some aircraft . The world's largest diesel engines put in service are 14-cylinder, two-stroke marine diesel engines; they produce a peak power of almost 100 MW each. Diesel engines may be designed with either two-stroke or four-stroke combustion cycles . They were originally used as
4469-423: Is a simplified and idealised representation of the events involved in a diesel engine cycle, arranged to illustrate the similarity with a Carnot cycle . Starting at 1, the piston is at bottom dead centre and both valves are closed at the start of the compression stroke; the cylinder contains air at atmospheric pressure. Between 1 and 2 the air is compressed adiabatically – that is without heat transfer to or from
Mercedes-Benz Econic - Misplaced Pages Continue
4578-431: Is also avoided compared with non-direct-injection gasoline engines, as unburned fuel is not present during valve overlap, and therefore no fuel goes directly from the intake/injection to the exhaust. Low-speed diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) can reach effective efficiencies of up to 55%. The combined cycle gas turbine (Brayton and Rankine cycle)
4687-403: Is approximately 5 MW. Medium-speed engines are used in large electrical generators, railway diesel locomotives , ship propulsion and mechanical drive applications such as large compressors or pumps. Medium speed diesel engines operate on either diesel fuel or heavy fuel oil by direct injection in the same manner as low-speed engines. Usually, they are four-stroke engines with trunk pistons;
4796-429: Is called scavenging . The pressure required is approximately 10-30 kPa. Due to the lack of discrete exhaust and intake strokes, all two-stroke diesel engines use a scavenge blower or some form of compressor to charge the cylinders with air and assist in scavenging. Roots-type superchargers were used for ship engines until the mid-1950s, however since 1955 they have been widely replaced by turbochargers. Usually,
4905-404: Is done on the system to which the engine is connected. During this expansion phase the volume of the gas rises, and its temperature and pressure both fall. At 4 the exhaust valve opens, and the pressure falls abruptly to atmospheric (approximately). This is unresisted expansion and no useful work is done by it. Ideally the adiabatic expansion should continue, extending the line 3–4 to the right until
5014-427: Is hinged at the rear and lifts at the front, allowing the material in the bed to be unloaded ("dumped") on the ground behind the truck. Flatbed trucks have an entirely flat, level platform body. This allows for quick and easy loading but has no protection for the load. Hanging or removable sides are sometimes fitted, often in the form of a stakebody . Refrigerator trucks have insulated panels as walls and
5123-422: Is in neutral, it allows the engine speed to drop and synchronize engine and transmission revolutions relative to the road speed. Downshifting is performed in a similar fashion, except the engine speed is now required to increase (while the transmission is in neutral) just the right amount in order to achieve the synchronization for a smooth, non-collision gear change. "Skip changing" is also widely used; in principle,
5232-464: Is more complicated to make but allows the highest fuel efficiency; since the early 1980s, manufacturers such as MAN and Sulzer have switched to this system. It is standard for modern marine two-stroke diesel engines. So-called dual-fuel diesel engines or gas diesel engines burn two different types of fuel simultaneously , for instance, a gaseous fuel and diesel engine fuel. The diesel engine fuel auto-ignites due to compression ignition, and then ignites
5341-573: Is most often made as vans. Medium trucks are larger than light but smaller than heavy trucks. In the US, they are defined as weighing between 13,000 and 33,000 lb (5.9 and 15.0 t). For the UK and the EU the weight is between 3.5 and 7.5 t (7,700 and 16,500 lb). Local delivery and public service ( dump trucks , garbage trucks and fire-fighting trucks ) are normally around this size. Heavy trucks are
5450-461: Is mostly reserved for larger vehicles. In Australia and New Zealand, a pickup truck is frequently called a ute (short for "utility" vehicle), while in South Africa it is called a bakkie ( Afrikaans : "small open container"). In the United Kingdom, India, Malaysia, Singapore, Ireland, and Hong Kong lorry is used instead of truck , but only for the medium and heavy types, while truck
5559-469: Is not definitive. The expanded meaning of lorry , "self-propelled vehicle for carrying goods", has been in usage since 1911. In the United States, Canada, and the Philippines, "truck" is usually reserved for commercial vehicles larger than regular passenger cars, but includes large SUVs, pickups, and other vehicles with an open load bed. In Australia, New Zealand and South Africa, the word "truck"
SECTION 50
#17328016219345668-412: Is released and the clutch pedal is depressed while the gear lever is moved into neutral, the clutch pedal is then released and quickly pushed down again while the gear lever is moved to the next higher gear. Finally, the clutch pedal is released and the accelerator pedal pushed down to obtain the required engine speed. Although this is a relatively fast movement, perhaps a second or so while the transmission
5777-516: Is used almost exclusively to refer to pickups . Often produced as variations of golf cars , with internal combustion or battery electric drive , these are used typically for off-highway use on estates, golf courses, and parks. While not suitable for highway use some variations may be licensed as slow speed vehicles for operation on streets, generally as a body variation of a neighborhood electric vehicle . A few manufactures produce specialized chassis for this type of vehicle, while Zap Motors markets
5886-507: The EU average for diesel cars at the time accounted for half of newly registered cars. However, air pollution and overall emissions are more difficult to control in diesel engines compared to gasoline engines, and the use of diesel auto engines in the U.S. is now largely relegated to larger on-road and off-road vehicles . Though aviation has traditionally avoided using diesel engines, aircraft diesel engines have become increasingly available in
5995-552: The European Union , vehicles with a gross combination mass of up to 3.5 t (3.4 long tons; 3.9 short tons) are defined as light commercial vehicles , and those over as large goods vehicles . Trucks and cars have a common ancestor: the steam-powered fardier Nicolas-Joseph Cugnot built in 1769. However, steam wagons were not common until the mid-19th century. The roads of the time, built for horse and carriages, limited these vehicles to very short hauls, usually from
6104-722: The United Kingdom , and the United States for "Method of and Apparatus for Converting Heat into Work". In 1894 and 1895, he filed patents and addenda in various countries for his engine; the first patents were issued in Spain (No. 16,654), France (No. 243,531) and Belgium (No. 113,139) in December 1894, and in Germany (No. 86,633) in 1895 and the United States (No. 608,845) in 1898. Diesel
6213-496: The cab-over configuration in North America, to provide better maneuverability in tight situations. They are also among the most severe-duty and highest GVWR trucks on public roads. Semi-tractors ("artics" in the UK) have a fifth wheel for towing a semi-trailer instead of a body. Diesel engine The diesel engine , named after the German engineer Rudolf Diesel , is an internal combustion engine in which ignition of
6322-422: The diesel engine did not appear in production trucks until Benz introduced it in 1923. The diesel engine was not common in trucks in Europe until the 1930s. In the United States, Autocar introduced diesel engines for heavy applications in the mid-1930s. Demand was high enough that Autocar launched the "DC" model (diesel conventional) in 1939. However, it took much longer for diesel engines to be broadly accepted in
6431-503: The fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression ; thus, the diesel engine is called a compression-ignition engine (CI engine). This contrasts with engines using spark plug -ignition of the air-fuel mixture, such as a petrol engine ( gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas ). Diesel engines work by compressing only air, or air combined with residual combustion gases from
6540-461: The phase-out of fossil fuel vehicles includes trucks. According to The Economist magazine "Electric lorries will probably run on hydrogen, not batteries, which are too expensive." Other researchers say that once faster chargers are available batteries will become competitive against diesel for all, except perhaps the heaviest, trucks. Small trucks use the same type of transmissions as almost all cars, having either an automatic transmission or
6649-416: The 21st century. Since the late 1990s, for various reasons—including the diesel's inherent advantages over gasoline engines, but also for recent issues peculiar to aviation—development and production of diesel engines for aircraft has surged, with over 5,000 such engines delivered worldwide between 2002 and 2018, particularly for light airplanes and unmanned aerial vehicles . In 1878, Rudolf Diesel , who
SECTION 60
#17328016219346758-454: The Carnot cycle. Diesel was also introduced to a fire piston , a traditional fire starter using rapid adiabatic compression principles which Linde had acquired from Southeast Asia . After several years of working on his ideas, Diesel published them in 1893 in the essay Theory and Construction of a Rational Heat Motor . Diesel was heavily criticised for his essay, but only a few found
6867-545: The US, no more than 13,900 lb (6.3 t)) and are used by individuals and businesses alike. In the EU they may not weigh more than 3.5 t (7,700 lb) and are allowed to be driven with a driving licence for cars. Pickup trucks , called utes in Australia and New Zealand, are common in North America and some regions of Latin America, Asia, and Africa, but not so in Europe, where this size of commercial vehicle
6976-558: The US: gasoline engines were still in use on heavy trucks in the 1970s. Electrically powered trucks predate internal combustion ones and have been continuously available since the mid-19th-century. In the 1920s Autocar Trucks was the first of the major truck manufacturers to offer a range of electric trucks for sale. Electric trucks were successful for urban delivery roles and as specialized work vehicles like forklifts and pushback tugs . The higher energy density of liquid fuels soon led to
7085-400: The amount of fuel injected into the engine. Due to the amount of air being constant (for a given RPM) while the amount of fuel varies, very high ("lean") air-fuel ratios are used in situations where minimal torque output is required. This differs from a petrol engine, where a throttle is used to also reduce the amount of intake air as part of regulating the engine's torque output. Controlling
7194-403: The axles. The holes in rails are used either for mounting vehicle components and running wires and hoses or measuring and adjusting the orientation of the rails at the factory or repair shop. The frame is usually made of steel , but can be made (whole or in part) of aluminum for a lighter weight. A tow bar may be found attached at one or both ends, but heavy tractors almost always make use of
7303-470: The bore is smaller than the stroke. Low-speed diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) often have an effective efficiency of up to 55%. Like medium-speed engines, low-speed engines are started with compressed air, and they use heavy oil as their primary fuel. Four-stroke engines use the combustion cycle described earlier. Most smaller diesels, for vehicular use, for instance, typically use
7412-650: The case of refuse trucks , fire trucks , concrete mixers , and suction excavators . In American English, a commercial vehicle without a trailer or other articulation is formally a "straight truck" while one designed specifically to pull a trailer is not a truck but a " tractor ". The majority of trucks currently in use are powered by diesel engines , although small- to medium-size trucks with gasoline engines exist in North America . Electrically powered trucks are more popular in China and Europe than elsewhere. In
7521-448: The combustion chamber, the droplets continue to vaporise from their surfaces and burn, getting smaller, until all the fuel in the droplets has been burnt. Combustion occurs at a substantially constant pressure during the initial part of the power stroke. The start of vaporisation causes a delay before ignition and the characteristic diesel knocking sound as the vapour reaches ignition temperature and causes an abrupt increase in pressure above
7630-418: The combustion chamber. This may be into a (typically toroidal ) void in the top of the piston or a pre-chamber depending upon the design of the engine. The fuel injector ensures that the fuel is broken down into small droplets, and that the fuel is distributed evenly. The heat of the compressed air vaporises fuel from the surface of the droplets. The vapour is then ignited by the heat from the compressed air in
7739-425: The compressed gas. Combustion and heating occur between 2 and 3. In this interval the pressure remains constant since the piston descends, and the volume increases; the temperature rises as a consequence of the energy of combustion. At 3 fuel injection and combustion are complete, and the cylinder contains gas at a higher temperature than at 2. Between 3 and 4 this hot gas expands, again approximately adiabatically. Work
7848-452: The compression ratio in a spark-ignition engine where fuel and air are mixed before entry to the cylinder is limited by the need to prevent pre-ignition , which would cause engine damage. Since only air is compressed in a diesel engine, and fuel is not introduced into the cylinder until shortly before top dead centre ( TDC ), premature detonation is not a problem and compression ratios are much higher. The pressure–volume diagram (pV) diagram
7957-473: The compression required for his cycle: By June 1893, Diesel had realised his original cycle would not work, and he adopted the constant pressure cycle. Diesel describes the cycle in his 1895 patent application. Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion. Now it is simply stated that the compression must be sufficient to trigger ignition. In 1892, Diesel received patents in Germany , Switzerland ,
8066-416: The concept of air-blast injection from George B. Brayton , albeit that Diesel substantially improved the system. On 17 February 1894, the redesigned engine ran for 88 revolutions – one minute; with this news, Maschinenfabrik Augsburg's stock rose by 30%, indicative of the tremendous anticipated demands for a more efficient engine. On 26 June 1895, the engine achieved an effective efficiency of 16.6% and had
8175-424: The cost of smaller ships and increases their transport capacity. In addition to that, a single ship can use two smaller engines instead of one big engine, which increases the ship's safety. Low-speed diesel engines are usually very large in size and mostly used to power ships . There are two different types of low-speed engines that are commonly used: Two-stroke engines with a crosshead, and four-stroke engines with
8284-431: The decline of electric-powered trucks in favor of, first, gasoline, and then diesel and CNG-fueled engines until battery technology advanced in the 2000s when new chemistries and higher-volume production broadened the range of applicability of electric propulsion to trucks in many more roles. Today, manufacturers are electrifying all trucks ahead of national regulatory requirements, with long-range over-the-road trucks being
8393-616: The diesel engine is Diesel's "very own work" and that any "Diesel myth" is " falsification of history ". Diesel sought out firms and factories that would build his engine. With the help of Moritz Schröter and Max Gutermuth [ de ] , he succeeded in convincing both Krupp in Essen and the Maschinenfabrik Augsburg . Contracts were signed in April 1893, and in early summer 1893, Diesel's first prototype engine
8502-417: The efficiency is much lower, with efficiencies of up to 43% for passenger car engines, up to 45% for large truck and bus engines, and up to 55% for large two-stroke marine engines. The average efficiency over a motor vehicle driving cycle is lower than the diesel engine's peak efficiency (for example, a 37% average efficiency for an engine with a peak efficiency of 44%). That is because the fuel efficiency of
8611-408: The environment – by the rising piston. (This is only approximately true since there will be some heat exchange with the cylinder walls .) During this compression, the volume is reduced, the pressure and temperature both rise. At or slightly before 2 (TDC) fuel is injected and burns in the compressed hot air. Chemical energy is released and this constitutes an injection of thermal energy (heat) into
8720-406: The exhaust (known as exhaust gas recirculation , "EGR"). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases air temperature inside the cylinder so that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of fuel is uneven; this is called
8829-493: The first internal combustion truck. Later that year some of Benz's trucks were modified to become busses by Netphener . A year later, in 1896, another internal combustion engine truck was built by Gottlieb Daimler , the Daimler Motor Lastwagen . Other companies, such as Peugeot , Renault and Büssing , also built their own versions. The first truck in the United States was built by Autocar in 1899 and
8938-463: The four-stroke cycle. This is due to several factors, such as the two-stroke design's narrow powerband which is not particularly suitable for automotive use and the necessity for complicated and expensive built-in lubrication systems and scavenging measures. The cost effectiveness (and proportion of added weight) of these technologies has less of an impact on larger, more expensive engines, while engines intended for shipping or stationary use can be run at
9047-616: The fuel and forced it into the engine through a nozzle (a similar principle to an aerosol spray). The nozzle opening was closed by a pin valve actuated by the camshaft . Although the engine was also required to drive an air compressor used for air-blast injection, the efficiency was nonetheless better than other combustion engines of the time. However the system was heavy and it was slow to react to changing torque demands, making it unsuitable for road vehicles. A unit injector system, also known as "Pumpe-Düse" ( pump-nozzle in German) combines
9156-700: The fuel injection transformed the direct injection engine by allowing much greater control over the combustion. Common rail (CR) direct injection systems do not have the fuel metering, pressure-raising and delivery functions in a single unit, as in the case of a Bosch distributor-type pump, for example. A high-pressure pump supplies the CR. The requirements of each cylinder injector are supplied from this common high pressure reservoir of fuel. An Electronic Diesel Control (EDC) controls both rail pressure and injections depending on engine operating conditions. The injectors of older CR systems have solenoid -driven plungers for lifting
9265-405: The fuel pump measures out the correct amount of fuel and determines the timing of each injection. These engines use injectors that are very precise spring-loaded valves that open and close at a specific fuel pressure. Separate high-pressure fuel lines connect the fuel pump with each cylinder. Fuel volume for each single combustion is controlled by a slanted groove in the plunger which rotates only
9374-461: The gaseous fuel. Such engines do not require any type of spark ignition and operate similar to regular diesel engines. The fuel is injected at high pressure into either the combustion chamber , "swirl chamber" or "pre-chamber," unlike petrol engines where the fuel is often added in the inlet manifold or carburetor . Engines where the fuel is injected into the main combustion chamber are called direct injection (DI) engines, while those which use
9483-443: The heavier trucks use four-stroke diesel engines with a turbocharger and intercooler . Huge off-highway trucks use locomotive-type engines such as a V12 Detroit Diesel two stroke engine. A large proportion of refuse trucks in the United States employ CNG (compressed natural gas) engines for their low fuel cost and reduced carbon emissions. A significant proportion of North American manufactured trucks use an engine built by
9592-440: The highest in the world, a B-double can weigh 62.5 t (61.5 long tons; 68.9 short tons) and be 25 m (82 ft) long, and road trains used in the outback can weigh 172 t (169.3 long tons; 189.6 short tons) and be 53.5 m (176 ft) long. The European Union also has complex regulations. The number and spacing of axles, steering, single or dual tires, and suspension type all affect maximum weights. Length of
9701-419: The injection needle, whilst newer CR injectors use plungers driven by piezoelectric actuators that have less moving mass and therefore allow even more injections in a very short period of time. Early common rail system were controlled by mechanical means. The injection pressure of modern CR systems ranges from 140 MPa to 270 MPa. An indirect diesel injection system (IDI) engine delivers fuel into
9810-553: The injector and fuel pump into a single component, which is positioned above each cylinder. This eliminates the high-pressure fuel lines and achieves a more consistent injection. Under full load, the injection pressure can reach up to 220 MPa. Unit injectors are operated by a cam and the quantity of fuel injected is controlled either mechanically (by a rack or lever) or electronically. Due to increased performance requirements, unit injectors have been largely replaced by common rail injection systems. The average diesel engine has
9919-407: The largest on-road trucks, Class 8 . These include vocational applications such as heavy dump trucks, concrete pump trucks, and refuse hauling, as well as ubiquitous long-haul 4x2 and 6×4 tractor units . Road damage and wear increase very rapidly with the axle weight. The number of steering axles and the suspension type also influence the amount of the road wear. In many countries with good roads
10028-521: The last remaining major independent engine manufacturer ( Cummins ) but most global OEMs such as Volvo Trucks and Daimler AG promote their own "captive" engines. In the European Union, all new truck engines must comply with Euro VI emission regulations, and Euro 7 from the late 2020s has stricter exhaust limits and also limits air pollution from brakes and tires . As of 2019 several alternative technologies are competing to displace
10137-476: The mistake that he made; his rational heat motor was supposed to utilise a constant temperature cycle (with isothermal compression) that would require a much higher level of compression than that needed for compression ignition. Diesel's idea was to compress the air so tightly that the temperature of the air would exceed that of combustion. However, such an engine could never perform any usable work. In his 1892 US patent (granted in 1895) #542846, Diesel describes
10246-662: The most challenging. Truck is used in American English ; the British English equivalent is lorry. The first known usage of "truck" was in 1611 when it referred to the small strong wheels on ships' cannon carriages, and comes from "Trokhos" (Greek) = "wheel". In its extended usage, it came to refer to carts for carrying heavy loads, a meaning known since 1771. Its expanded application to "motor-powered load carrier" has been in usage since 1930, shortened from "motor truck", which dates back to 1901. "Lorry" has
10355-424: The operation is the same as double-clutching, but it requires neutral be held slightly longer than a single-gear change. Common North American setups include 9, 10, 13, 15, and 18 speeds. Automatic and automated manual transmissions for heavy trucks are becoming more and more common, due to advances both in transmission and engine power. In Europe, 8, 10, 12, and 16 gears are common on larger trucks with
10464-534: The past, however electronic governors are more common on modern engines. Mechanical governors are usually driven by the engine's accessory belt or a gear-drive system and use a combination of springs and weights to control fuel delivery relative to both load and speed. Electronically governed engines use an electronic control unit (ECU) or electronic control module (ECM) to control the fuel delivery. The ECM/ECU uses various sensors (such as engine speed signal, intake manifold pressure and fuel temperature) to determine
10573-480: The piston (not shown on the P-V indicator diagram). When combustion is complete the combustion gases expand as the piston descends further; the high pressure in the cylinder drives the piston downward, supplying power to the crankshaft. As well as the high level of compression allowing combustion to take place without a separate ignition system, a high compression ratio greatly increases the engine's efficiency. Increasing
10682-403: The piston-cylinder combination between 2 and 4. The difference between these two increments of work is the indicated work output per cycle, and is represented by the area enclosed by the pV loop. The adiabatic expansion is in a higher pressure range than that of the compression because the gas in the cylinder is hotter during expansion than during compression. It is for this reason that the loop has
10791-417: The pollutants can be removed from the exhaust gas using exhaust gas treatment technology. Road vehicle diesel engines have no sulfur dioxide emissions, because motor vehicle diesel fuel has been sulfur-free since 2003. Helmut Tschöke argues that particulate matter emitted from motor vehicles has negative impacts on human health. The particulate matter in diesel exhaust emissions is sometimes classified as
10900-408: The pressure falls to that of the surrounding air, but the loss of efficiency caused by this unresisted expansion is justified by the practical difficulties involved in recovering it (the engine would have to be much larger). After the opening of the exhaust valve, the exhaust stroke follows, but this (and the following induction stroke) are not shown on the diagram. If shown, they would be represented by
11009-544: The test bench. In the January 1896 report, this was considered a success. In February 1896, Diesel considered supercharging the third prototype. Imanuel Lauster , who was ordered to draw the third prototype " Motor 250/400 ", had finished the drawings by 30 April 1896. During summer that year the engine was built, it was completed on 6 October 1896. Tests were conducted until early 1897. First public tests began on 1 February 1897. Moritz Schröter 's test on 17 February 1897
11118-890: The timing of the start of injection of fuel into the cylinder is similar to controlling the ignition timing in a petrol engine. It is therefore a key factor in controlling the power output, fuel consumption and exhaust emissions. There are several different ways of categorising diesel engines, as outlined in the following sections. Günter Mau categorises diesel engines by their rotational speeds into three groups: High-speed engines are used to power trucks (lorries), buses , tractors , cars , yachts , compressors , pumps and small electrical generators . As of 2018, most high-speed engines have direct injection . Many modern engines, particularly in on-highway applications, have common rail direct injection . On bigger ships, high-speed diesel engines are often used for powering electric generators. The highest power output of high-speed diesel engines
11227-592: The truck can have on the Interstate highway system. Each State determines the maximum permissible vehicle , combination , and axle weight on state and local roads. Uniquely, the State of Michigan has a gross vehicle weight limit of 164,000 lb (74 t), which is twice the U.S. federal limit. A measure to change the law was defeated in the Michigan Senate in 2019. Almost all trucks share
11336-405: The use of diesel engines in heavy trucks. CNG engines are widely used in the US refuse industry and in concrete mixers, among other short-range vocations, but range limitations have prevented their broader uptake in freight hauling applications. Heavy electric trucks and hydrogen-powered trucks are new to the market in 2021, but major freight haulers are interested. Although cars will be first
11445-532: Was a student at the "Polytechnikum" in Munich , attended the lectures of Carl von Linde . Linde explained that steam engines are capable of converting just 6–10% of the heat energy into work, but that the Carnot cycle allows conversion of much more of the heat energy into work by means of isothermal change in condition. According to Diesel, this ignited the idea of creating a highly efficient engine that could work on
11554-488: Was attacked and criticised over several years. Critics claimed that Diesel never invented a new motor and that the invention of the diesel engine is fraud. Otto Köhler and Emil Capitaine [ de ] were two of the most prominent critics of Diesel's time. Köhler had published an essay in 1887, in which he describes an engine similar to the engine Diesel describes in his 1893 essay. Köhler figured that such an engine could not perform any work. Emil Capitaine had built
11663-635: Was available with 5 or 8 horsepower (4 or 6 kW) engines. Another early American truck was built by George Eldridge of Des Moines, Iowa, in 1903. It was powered by an engine with two opposed cylinders, and had a chain drive A 1903 Eldridge truck is displayed at the Iowa 80 Trucking Museum, Walcott, Iowa. Trucks of the era mostly used two-cylinder engines and had a carrying capacity of 1.5 to 2 t (3,300 to 4,400 lb). After World War I, several advances were made: electric starters , and 4, 6, and 8 cylinder engines. Although it had been invented in 1897,
11772-477: Was built in Augsburg . On 10 August 1893, the first ignition took place, the fuel used was petrol. In winter 1893/1894, Diesel redesigned the existing engine, and by 18 January 1894, his mechanics had converted it into the second prototype. During January that year, an air-blast injection system was added to the engine's cylinder head and tested. Friedrich Sass argues that, it can be presumed that Diesel copied
11881-424: Was the main test of Diesel's engine. The engine was rated 13.1 kW with a specific fuel consumption of 324 g·kW ·h , resulting in an effective efficiency of 26.2%. By 1898, Diesel had become a millionaire. The characteristics of a diesel engine are The diesel internal combustion engine differs from the gasoline powered Otto cycle by using highly compressed hot air to ignite the fuel rather than using
#933066