Showing posts with label Mechanical. Show all posts
Showing posts with label Mechanical. Show all posts

Tuesday, March 17, 2009

Telematics

The word Telematics is an amalgamation of the German words “Telekomunikaton” (telecommunication) and “infomatik” (information). It is the blending of computers and wireless telecommunications technologies, ostensibly the goal of efficiently conveying information over vast networks to improve a host of business functions or government-related public services. The most notable example of Telematics may be the Internet itself, since it depends on a number of computer networks connected globally through telecommunication backbones.


Telematics is the combination of telecommunications and new information technology. It has both a hardware component, such as cabling, computers, digitalisation and application components, and incorporates services provided by this new combination of telecommunication and information technology.


Telematics gives four new types of opportunity in the field of of information

Access to large quantities of information

Access to information of higher quality

Access to information over any distance, including global distances

Very rapid access to information

Tyre Threading

A tyre is a cushion provided with an automobile wheel. It consists of mainly the outer tyre and the inner tube. The air inside the tube carries the entire load and provides the cushion.

The functions of a tyre are


  1. To support the vehicle load
  2. To provide cushion against shocks
  3. To transmit driving and braking forces on the road
  4. To provide cornering power for smooth steering


Thread Patterns


1. Rib Shape

2. Lug Shape

3. Rib-Lug Shape

4. Block shape

5. Asymmetric Pattern

6. Directional Pattern


Gasoline direct injection or GDI

Gasoline direct injection or GDI is a variant of fuel injection employed in modern four stroke petrol engines. The gasoline or biobutanol is injected right into the combustion chamber of each cylinder, as opposed to conventional multi point fuel injection that happens in the intake manifold.

GDI enables stratified charge (ultra lean burn) combustion for improved fuel efficiency and emission levels at low load. Further improving efficiency and high-load output-power, the engine power is governed by modulating fuel injection, like a diesel engine; as opposed to restricting intake airflow, like a conventional gas internal combustion engine.

http://liveimages.editorial.carsales.com.au/carsales/general/editorial/ge4619201697009684489.jpg

Valvetronic

The Valvetronic system is the first variable valve timing system to offer continuously variable timing (on both intake and exhaust camshafts) along with continuously variable intake valve lift, from ~0 to 10 mm, on the intake camshaft only. Valvetronic-equipped engines are unique in that they rely on the amount of valve lift to throttle the engine rather than a butterfly valve in the intake tract. In other words, in normal driving, the 'gas pedal' controls the Valvetronic hardware rather than the throttle plate

First introduced by BMW on the 316ti compact in 2001, Valvetronic has since been added to many of BMW's engines. The Valvetronic system is coupled with BMW's proven double-VANOS, to further enhance both power and efficiency across the engine speed range. Valvetronic will not be coupled to BMW's N53 and N54, 'High Precision Injection' (gasoline direct injection) technology due to lack of room in the cylinder head.

Cylinder heads with Valvetronic use an extra set of rocker arms, called intermediate arms (lift scaler), positioned between the valve stem and the camshaft. These intermediate arms are able to pivot on a central point, by means of an extra, electronicly actuated camshaft. This movement alone, without any movement of the intake camshaft, can open or close the intake valves.

Valvetronic
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Because the intake valves now have the ability to move from fully closed to fully open positions, and everywhere in between, the primary means of engine load control is transferred from the throttle plate to the intake valvetrain. By eliminating the throttle plate's 'bottleneck' in the intake track, pumping losses are reduced, fuel economy and responsiveness are improved

VANOS (Variable Nockenwellen Steuerung)

VANOS (Variable Nockenwellen Steuerung) is an automobile variable valve timing technology developed by BMW in close collaboration with Continental Teves. VANOS varies the duration of the intake valves by moving the position of the camshafts in relation to the drive gear. This movement varies from 6degrees of advanced to 6degrees of retarded camshaft timing. BMW recently began offering 'double' VANOS, which operates on the exhaust camshaft as well, on a number of its cars.
Variable Ventil-Steuerzeiten mit dem BMW-Doppel-VANOS (Variable Nockenwellen Steuerung) (Foto)

Ball valve

A ball valve (like the butterfly valve, one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked. The handle position lets you 'see' the valve's position.

Ball valves are durable and usually work to achieve perfect shutoff even after years of disuse. They are therefore an excellent choice for shutoff applications (and are often preferred to globe valves and gate valves for this purpose). They do not offer the fine control that may be necessary in throttling applications but are sometimes used for this purpose.

Fig. 12.2.1  Ball valve (shown in its open position)

The body of ball valves may be made of metal, ceramic, or plastic. The ball may be chrome plated to make it more durable.

There are three general types of ball valves: full port, standard port, and reduced port.

  • A full port ball valve has an oversized ball so that the hole in the ball is the same size as the pipeline resulting in lower friction loss. Flow is unrestricted, but the valve is larger.
  • A standard port ball valve is usually less expensive, but has a smaller ball and a correspondingly smaller port. Flow through this valve is one pipe size smaller than the valve's pipe size resulting in slightly restricted flow.
  • In reduced port ball valves, flow through the valve is two pipe sizes smaller than the valve's pipe size resulting in restricted flow.
A trunnion ball valve has a mechanical means of anchoring the ball at the top and the bottom

Gate valve

A gate valve is a valve that opens by lifting a round or rectangular gate out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar. The gate faces can form a wedge shape or they can be parallel. Gate valves are sometimes used for regulating flow, but many are not suited for that purpose, having been designed to be fully opened or closed. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.


Gate valves are characterised as having either a rising or a nonrising stem. Rising stems provide a visual indication of valve position. Nonrising stems are used where vertical space is limited or underground.

Bonnets provide leakproof closure for the valve body. Gate valves may have a screw-in, union, or bolted bonnet. Screw-in bonnet is the simplest, offering a durable, pressure-tight seal. Union bonnet is suitable for applications requiring frequent inspection and cleaning. It also gives the body added strength. Bolted bonnet is used for larger valves and higher pressure applications.

Another type of bonnet construction in a gate valve is pressure seal bonnet. This construction is adopted for valves for high pressure service, typically in excess of 2250 psi. The unique feature about the pressure seal bonnet is that the body - bonnet joints seals improves as the internal pressure in the valve increases, compared to other constructions where the increase in internal pressure tends to create leaks in the body-bonnet joint.


Globe valves

Globe valves are named for their spherical body shape. The two halves of the valve body are separated by a baffle with a disc in the center. Globe valves operate by screw action of the handwheel. They are used for applications requiring throttling and frequent operation. Since the baffle restricts flow, they're not recommended where full, unobstructed flow is required.

A bonnet provides leakproof closure for the valve body. Globe valves may have a screw-in, union, or bolted bonnet. Screw-in bonnet is the simplest bonnet, offering a durable, pressure-tight seal. Union bonnet is suitable for applications requiring frequent inspection or cleaning. It also gives the body added strength. Bolted bonnet is used for larger or higher pressure applications.


Many globe valves have a class rating that corresponds to the pressure specifications of ANSI 16.34. Other different types of valve usually are called globe style valves because of the shape of the body or the way of closure of the disk. As an example typical swing check valves could be called globe type.

VVT-i

VVT-i, or Variable Valve Timing with intelligence, is an automobile variable valve timing technology developed by Toyota. The Toyota VVT-i system replaces the Toyota VVT offered starting in 1991 on the 4A-GE 20-Valve engine. The VVT system is a 2-stage hydraulically controlled cam phasing system.

Toyota Valvematic

VVT-i, introduced in 1996, varies the timing of the intake valves by adjusting the relationship between the camshaft drive (belt, scissor-gear or chain) and intake camshaft. Engine oil pressure is applied to an actuator to adjust the camshaft position. In 1998, 'Dual' VVT-i (adjusts both intake and exhaust camshafts) was first introduced in the RS200 Altezza's 3S-GE engine. Dual VVT-i is also found in Toyota's new generation V6 engine, the 3.5L 2GR-FE V6. This engine can be found in the Avalon, RAV4, and Camry in the US, the Aurion in Australia, and various models in Japan, including the Estima. Other Dual VVT-i engines will be seen in upcoming Toyota models, including a new 4 cylinder Dual VVT-i engine for the new generation 2007/2008 Corolla. Another notable implementation of the Dual VVT-i is the 2GR-FSE D-4S engine of the Lexus GS450h. By adjusting the valve timing, engine start and stop occur virtually unnoticable at minimum compression, and fast heating of the catalytic converter to its light-off temperature is possible, thereby reducing HC emissions considerably.

VTEC

VTEC (standing for Variable valve Timing and lift Electronic Control) is a system developed by Honda to improve the combustion efficiency of its internal combustion engines throughout the RPM range. This was the first system of its kind and eventually led to different types of variable valve timing and lift control systems that were later designed by other manufacturers (VVTL-i from Toyota, VarioCam Plus from Porsche, and so on). It was invented by Honda's chief engine designer Kenichi Nagahiro.

vtec work


catalytic converter

A catalytic converter automobiles in the (colloquially, 'cat' or 'catcon') is a device used to reduce the toxicity of emissions from an internal combustion engine. First widely introduced on series-productionUS market for the 1975 model year to comply with tightening EPA regulations on auto exhaust, catalytic converters are still most commonly used in motor vehicle exhaust systems. Catalytic converters are also used on generator sets, forklifts, mining equipment, trucks, buses, trains, and other engine-equipped machines. A catalytic converter provides an environment for a chemical reaction wherein toxic combustion byproducts are converted to less-toxic gases. The catalytic converter was invented at Trinity College (Connecticut).

catalytic converter

MegaSquirt

MegaSquirt is an aftermarket electronic fuel injection (EFI) controller designed to be used with a wide range of internal combustion engines. It is an open project headed by Bruce Bowling and Al Grippo, engineers that work on the U.S. East Coast. The project's do-it-yourself approach makes it the least-expensive system for this purpose. Basic costs are below US$200 as of 2005, although this can vary widely depending on application.

MegaSquirt is a successor of sorts to Bowling and Grippo's earlier EFI332 design, which was more complex yet more powerful system (at least initially). The EFI332 project started around 1995, and culminated in the release of about 200 kits in 2000. The system used a 32-bit MC68332 microcontroller from Motorola, hence the name. A steep learning curve is believed to have prevented the system from gaining wider acceptance.

The two engineers decided to simplify the design and focus on managing the fuel injectors (the EFI332 could also control the spark plug ignition system if so desired). The version 1.0 MegaSquirt used an 8-bit Motorola MC68HC908 microcontroller, but a later MegaSquirt-II upgrade included a 16-bit MC9S12. It is likely that a future version will use a 32-bit processor.

The assembled controller takes input from a few different sensors in order to manage the fuel injectors, including a throttle position sensor (TPS), exhaust gas oxygen sensor (EGO or O2intake air temperature sensor (IAT), and a coolant temperature sensor sensor), MAP sensor, (CLT). The latter two sensors themselves are usually the General Motors type, although you can recalibrate the controller to use other sensors.

There are several related projects, including:

  • MegaJoltLite – an ignition system controller for the Ford Enhanced Distributorless Ignition System (EDIS)
  • UltraMegaSquirt – an integrated fuel injection and ignition controlle

Butterfly valve

A Butterfly valve is a type of flow control device, used to make a fluid start or stop flowing through a section of pipe. The valve is similar in operation to a ball valve. A flat circular plate is positioned in the center of the pipe. The plate has a rod through it connected to a handle on the outside of the valve. Rotating the handle turns the plate either parallel or perpendicular to the flow of water, shutting off the flow. It is a very robust and reliable design. However, unlike the ball valve, the plate does not rotate out of the flow of water, so that a pressure drop is induced in the flow.

There are three types of butterfly valve:

  1. Resilient butterfly valve which has a flexible rubber seat. Working pressure up to 1.6 Mpa
  2. High performance butterfly valve which is usually double eccentric in design . Working pressure up to 5.0 Mpa
  3. Tricentric butterfly valve which is usually with metal seated design. Working pressure up to 10.0 Mpa

Butterfly valves are also commonly utilised in conjunction with carburetors to control the flow of air through the intake manifold and hence the flow of fuel and air into an internal combustion engine. The butterfly valve in this circumstance called a throttle as it is 'throttling' the engines aspiration. It is controlled via a cable or electronics by the furthest right pedal in the drivers footwell (although adaptions for hand control do exist). This is why the accelerator pedal in some countries is called a throttle pedal.

Weber carburetors

Weber carburetors were originally produced in Italy by Edoardo Weber as part of a conversion kit for 1920s Fiats. Weber pioneered the use of twin barrel carburetors with two barrels (or venturi) of different sizes, the smaller one for low speed running and the larger one optimised for high speed use.

In the 1930s Weber began producing twin barrel carburetors for motor racing where two barrels of the same size were used. These were arranged so that each cylinder of the engine has its own carburetor barrel. These carburetors found use in Maserati and Alfa Romeo racing cars.

In time, Weber carburetors were fitted to standard production cars and factory racing applications on automotive marques such as Abarth, Alfa Romeo, Aston Martin, BMW, Ferrari, Fiat, Ford, Lamborghini, Lancia, Lotus, Maserati, Porsche, Triumph, and Volkswagen.

In the United States Weber Carburetors are sold for both street and off road use. They are sold in what is referred to as a Weber Conversion kit. A Weber conversion kit is a complete package of Weber Carburetor, intake manifold or manifold adapter, throttle linkage, air filter and all of the necessary hardware needed to install the Weber on a vehicle.

Diesel Particulate Filter

A Diesel Particulate Filter, sometimes called a DPF, is device designed to remove Diesel Particulate Matter or soot from the exhaust gas of a Diesel engine, most of which are rated at 85% efficiency, but often attaining efficiencies of over 90%. A Diesel-powered vehicle with a filter installed will emit no visible smoke from its exhaust pipe.

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In addition to collecting the particulate, a method must be designed to get rid of it. Some filters are single use (disposable), while others are designed to burn off the accumulated particulate, either through the use of a catalyst (passive), or through an active technology, such as a fuel burner which heats the filter to soot combustion temperatures, or through engine modifications (the engine is set to run a certain specific way when the filter load reachs a pre-determined level, either to heat the exhaust gasses, or to produce high amounts of No2, which will oxidize the particualte at relatively low temperatures). This procedure is known as 'filter regeneration.' Fuel sulfur interferes many 'Regeneration' strategies, and all jurisdictions that are interested in reduction of particulate emissions, are also passing regulations governing fuel sulfur levels.

Selective Catalytic Reduction (SCR)

Selective Catalytic Reduction (SCR), a process where a gaseous or liquid reductant (most commonly ammonia or urea) is added to the flue gas stream and is absorbed onto a catalyst. The reductant reacts with NOx in the flue gas to form H2O and N2.

Graphic showing a schematic of a selective catalytic reduction (SCR) system. A diesel engine equipped with a cooling system produces exhaust, which travels through a diesel particulate filter (DPF) toward an SCR catalyst. Before the hot exhaust reaches the SCR catalyst, Diesel Exhaust Fluid (DEF) from a DEF tank with control unit is injected into the exhaust. The mixed exhaust and DEF travel together into the SCR catalyst. Reactions in the SCR catalyst produce nitrogen and water, which are emitted to the environment.

Specialty Catalytic Converters are required to make an SCR system work, the current options being a Vanadium based catalyst, or a catalyst with Zeolites in the washcoat. In some jurisdictions use of a Vanadium based catalyst are frowned on (California) and the Zeolite type preferred, however Vanadium offers better performance.

SCR catalysts function well only within a narrow temperature window, and for OEM installations the Engine Control Unit is specially programmed to keep the exhaust gas temperature in that range


MAP sensor

A MAP sensor (manifold absolute pressure) is one of the sensors used in an internal combustion engine's electronic control system. Engines that use a MAP sensor are typically fuel injected. The manifold absolute pressure sensor provides instantaneous pressure information to the engine's electronic control unit (ECU). This is necessary to calculate air density and determine the engine's air mass flow rate, which in turn is used to calculate the appropriate fuel flow. (See stoichiometry.)

An engine control system that uses manifold absolute pressure to calculate air mass, is using the speed-density method. Engine speed (RPM) and air temperature are also necessary to complete the speed-density calculation. Not all fuel injected engines use a MAP sensor to infer mass air flow, some use a MAF sensor (mass air flow).


EURO V

EURO V is the most recent set in a series of mandatory European emission standards applying to new road vehicles sold in the EU. For heavy duty vehicles (lorries) the standards apply to vehicles brought on the market from October 2008. It requires Heavy Goods Vehicles (HGVs) to emit no more than 2.0 g/kWh of NOx and 0.02 g/kWh of PM. As yet, there is no Euro V standard applying for passenger cars, but a recent proposal suggests to limit diesel car emissions to 0.200 g/km of NOx and 0.005 g/km of Particulate Matter (PM), petrol cars to 0.060 g/km NOx and 0.005 g/km PM.

The standards do not mandate the application of specific technologies, but it is widely expected that diesel particulate filters will need to be fitted in diesel vehicles to comply with the PM standard

Click of the pic for a larger version

mass airflow sensor

A mass airflow sensor is used to determine the mass of air entering the engine. The air mass information is necessary to calculate and deliver the correct fuel mass to the engine. Air is a gas, and its density changes as it expands and contracts with temperature and pressure. In automotive applications, air density varies with the vehicle's operating environment, and is an ideal application for a mass sensor. (See stoichiometric, ideal gas law, and density.)

There are two common types of mass airflow sensors in usage on gasoline engines. They are the vane meter and the hot wire. Neither design employs technology that measures air mass directly. However, with an additional sensor or two, the engine's air mass flow rate can be accurately determined.

BlueTec

BlueTec is DaimlerChrysler's name for its two nitrogen oxide (NOx) reducing systems, for use in their Diesel automobile engines. One is a urea catalyst called AdBlue, the other is called DeNOx and uses an oxidising catalytic converter and particular filter combined with other NOx introduced the systems in the reducing systems. Both systems were designed to slash emissions further than ever before. Mercedes-BenzE-Class (using the 'DeNOx' system) and GL-Class (using 'AdBlue') at the 2006 North American International Auto Show as the E 320 and GL 320 Bluetec. This system makes these vehicles 45-state and 50-state legal respectively in the United States, and is expected to meet all emissions regulations through 2009. It also makes DaimlerChrysler the only car manufacturer in the the US committed to selling diesel models in the 2007 model year.
mercedes-bluetec-motor