Piston
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In
the crank mechanism piston performs several functions , including the
perception of the gas pressure and the transmission of forces on the rod
, sealing the combustion chamber and heat removal from it . The piston
is the most characteristic part in an internal combustion engine as is
realized with the help of thermodynamic process engine.Conditions in which it operates piston extreme and characterized by high pressure, temperature and inertial loads. at least from steel. The pistons are made of two ways - by injection molding or by stamping called forged pistons .
Scheme piston engine
The piston is integral structural element , which is conventionally divided into head (some sources call it the bottom) and a skirt. The shape and design of the piston is largely determined by the type of engine , the shape of the combustion chamber and the combustion process occurring in it. Piston gasoline engine has a flat or near- flat surface of the head . It may be provided with grooves for the full valve opening . Pistons with direct fuel injection have a more complex shape. In the top of the piston diesel engine combustion chamber holds a certain form , which provides a nice twist and improves mixture formation .
Below the piston head run grooves for mounting piston rings. The piston skirt has a tapered or curved ( barrel ) form . Such a shape of the skirt of the piston compensates for thermal expansion during heating. When reaching the operating temperature of the engine piston takes a cylindrical shape. To reduce the friction losses on the piston side with a layer of antifriction material ( molybdenum disulfide, graphite) . In the piston skirt has holes with the tides ( the boss ) to secure the piston pin .
Piston cooling is carried out by the internal surface of a variety of ways :
oil mist in the cylinder;
oil splashing through the hole in the rod ;
oil splashes special nozzle ;
injection of oil into a special zone in the annular channel rings;
oil flow through the tubular coil in the piston crown .
Piston rings form a tight connection with the wall of the piston cylinder. They are made of cast iron modified . Piston rings are the main source of friction in the internal combustion engine. Friction losses in the rings reach to 25 % of mechanical loss in the engine.
The number and location of the rings depends upon the type and purpose of the engine . The most common scheme - two compression and one oil ring . Compression rings prevent breakthrough of gas from the combustion chamber into the crankcase . The first compression ring works in the most severe conditions. Therefore, a number of pistons of diesel and gasoline engines forced into the groove of the ring set steel insert that improves durability and allows to realize the maximum compression . Compression rings may have a trapezoidal , a barrel , a conical shape , some are performed with a cut ( notch ) .
Scraper ring removes the excess oil from the surface of the cylinder and prevents the ingress of oil into the combustion chamber . The ring has a plurality of drainage holes . Some designs have a spring ring expander .
Compound piston rod by means of a piston pin which has a tubular shape and is made of steel. There are several way to install the piston pin . The most popular so-called floating finger that has the ability to rotate in bosses and the piston rod head during operation. To prevent displacement of the finger he fixed retainer rings . Much less is applied rigidly fixed ends of the piston pin or rigid fastening pin into the piston rod head .
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The Car Body
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Car Body
So many owners of
Toyota and Jeep know, AW4/el Toyota 340, A340, and A341E series of
transmissions are generally very well made and demonstrate excellent durability
in unmodified applications. The
frame is present for transmitting extremely strong need be used in a high
performance use or end of duty.
The problem is that the original calibration is engineered for driver comfort rather than ultimate component is used as strength. The soft, sliding shifts that are part of the original design are not appropriate for use, the trailer increasing horsepower, use the road, racing, etc.
These calibration inadequacies quickly manifest themselves as extremely poor quality of the change, and often, severe damage to the gearbox is soon to we have follow. One of the most common symptoms of this is the engine stuttering or hitting the revolution limiter during a full throttle upshift.
Without getting in into too much technical detail, the factory defaults can be treated with the modification and recalibration of the control valve assembly, AKA the valve body.
The valve body is as called as or we can say as component that is comprised of valves, solenoids, an orifice separator plate and an intricate series of steps which is the most complex part of the more complex of the automatic transmission vehicle.
The problem is that the original calibration is engineered for driver comfort rather than ultimate component is used as strength. The soft, sliding shifts that are part of the original design are not appropriate for use, the trailer increasing horsepower, use the road, racing, etc.
These calibration inadequacies quickly manifest themselves as extremely poor quality of the change, and often, severe damage to the gearbox is soon to we have follow. One of the most common symptoms of this is the engine stuttering or hitting the revolution limiter during a full throttle upshift.
Without getting in into too much technical detail, the factory defaults can be treated with the modification and recalibration of the control valve assembly, AKA the valve body.
The valve body is as called as or we can say as component that is comprised of valves, solenoids, an orifice separator plate and an intricate series of steps which is the most complex part of the more complex of the automatic transmission vehicle.
The function of the valve body is to act as the "brain" of the automatic transmission that directs hydraulic pressure to the appropriate clutches and bands at the right time to initiate upshifts, down changes, backward selection, using clutch converter, etc.. as well as the timing of the change control and quality of change, is also responsible for directing hydraulic pressure to the cooler and the lubrication circuit.
As we you can imagine or you can say, the transmission's operational characteristics can be drastically altered and also customized to the given application with modifications to this component.
Because there is no commercially available kits of change for these transmissions, we began working on valve body modifications that were appropriate for Supras, Jeeps with the AW4 transmission, Toyota Tundra, the Tacoma and 4Runner, and also Lexus SUV and rear passenger car drive handle especially those requiring additional energy accompanying the installation of a supercharger, a turbocharger or a nitrous oxide injection.
At the risk of oversimplification, there are some things that are done in concert to create a much more favorable operation of the gearbox.
The first thing that needs to be done is to increase the operating pressure of the hydraulic pressure transmission is called "line pressure". The hydraulic functions of / or the transmission are based on this pressure which is especially of concern for these purposes is the clamping force applied to the clutches and bands to get them hold against engine torque.
In simple words we can say that, increased engine output is complemented by increased line pressure and the "rising clamp" on the clutches that can be compared to a performance clutch spring plate with a lot more pressure on a manual transmission vehicle.
The idea is to raise this pressure only slightly at light throttle but increase it by 30-40% at full throttle where it is really needed. The effects of this are changes that have not completed uncomfortable in lower openings of the throttle, while a heavier throttle, the signature changes to a much shorter time using the clutch and increasing the strength strengthening Clamp can be achieved.
An additional advantage of this is increased through the cooler and transmission lubrication system.
Secondly, the hydraulic pressure is normally routed through a hole in a metal "separator plate" which resides between the two halves of the valve body before it gets to its intended destination. Altering these holes can increase the volume of hydraulic oil which is used to apply the various clutches and bands.
The final part of modification is the alteration of the accumulator machine or we can say circuits. These are hydraulic circuits that are parallel to the components that are used to shift. Its function is to absorb or "accumulate" some of the hydraulic pressure that is intended to implement a package or a bandage clutch. By limiting the action of what is essentially a "shock absorber" for each shift, we can further reduce the time we lock up clutch and we shift the delay in throttle.
The end result is that the time of the change is reduced by 30 to 80% depending on the amount of shift feel and acceptable to the intended use. The clamping force required to apply the clutches and bands is increased to 30 to 40% full throttle. Cross the cooler and lube circuit increases and the time of use converter clutch is also reduced.
Improvements transmission body and valve are not only for American made vehicles more. The increased performance and more efficient shifting is now available for vehicles of almost every manufacturer thanks to the few companies that are willing to do the work of research and development required for this rapidly growing segment of the sold off or after all.
car engine
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INTRODUCTIONMany people at some point will have had the opportunity to see the outside of gasoline engine (also called "internal combustion engine" or "internal combustion"), but it is likely that many of these people also unaware of its internal .
When we decided to get a license to drive a car or any other motor vehicle, in some countries require a test or exam answer where, precisely, are some questions related to the working principle of thermal engines of internal combustion either gasoline or diesel.
Petrol engine car or modern automobile.
However, as a mere curiosity, maybe you'll have interested in knowing how a gasoline engine and what parts and pieces that make it up, but between your shorter-term projects is not precisely obtain a license conduction.
A gasoline engine is a thermodynamic machine comprises a set of mechanisms or parts fixed and movable, whose main function is to transform the chemical energy produced by combustion provides a mixture of air and fuel into mechanical energy or motion. When this transformation occurs chemical into mechanical energy can do useful work, for example, move a motor vehicle as a car or a car, or any other mechanism, as it might be an electrical generator.
Similarly, with the mechanical energy that provides a heat engine can move any other appropriate mechanism that engages the same such as an electrical generator, water pump, the blade of a lawnmower, etc.
Small gasoline engine mated to a lawn mower.
In general the internal combustion engines can be of two types, according to the fuel used to run:
Explosion or gasoline
Internal combustion diesel
While combustion engines using gasoline (or gas, or even alcohol) as fuel, the diesel internal combustion uses only diesel (diesel).
If you ever compare parts or mechanisms that shape structurally a gasoline engine and a diesel engine, we will see that in many respects are similar, while others are completely different, although in both cases the principle is similar.
Both petrol engines as diesels can be used to perform the same functions, but when it needs to develop great powers, as required to move a locomotive, a ship or an electrical generator generation large capacity are used only diesel internal combustion engines.
air suspension
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Air suspension with adjustable stiffness and ride height
Air suspension with adjustable stiffness and ride height is set to off-road vehicles or vehicles business class and is used to create additional comfort when driving.
Air suspension will reduce the ride height depending on the speed, and the center of gravity down and significantly increased exchange rate stability. The driver can choose from several levels of clearance.
The pressure in the strut is created by a separate compressor. All elements are combined with plastic ducts and the air flow is regulated by solenoid valves. The data from four sensors located on the axes, and three acceleration sensors mounted on the body, the control unit receives an adaptive air suspension. Thus, the computer in a few milliseconds gives the command to reconfigure each shock absorber, suspension depends on road.
Damping force is adjusted automatically. Under a heavy load in the harness supplied additional air that is discharged with decreasing load. In addition, the adaptive air suspension provides auto adjusting the ground clearance. In this case, the clearance of the car, regardless of the load remains within the specified values.
Infinitely variable rigidity air suspension is designed to provide a high level of comfort thanks to the computer control of the testimony of the various types of sensors.
While there is no need for tougher the suspension, for example, in high-speed driving on the road with good pavement, suspension remains comfortably soft. Changing the damping of each wheel individually reduces the risk of body movements, which could affect passenger comfort.
In cornering, or when driving off adaptive suspension automatically reduces the buildup of body and pecks.
The principle of operation of air suspension vehicle.
Characteristics of suspension affects many operational qualities of the car: ride, comfort, driving stability, durability, as the machine itself, and a number of its parts and components. In heavy traffic conditions, it is possible the suspension, not the engine power, determine the average and maximum speed.
Experience in operating commercial vehicles shows that the rough roads average speed drops to 35-40%, fuel consumption increases by 50-70%, turnaround decreases by 35-40%. The productivity of vehicles is reduced by 32-36%, and the cost of transport increased by 50-60%. Add to that the loss caused by overspending metal, fuel, rubber, and the incremental cost of labor. To reduce these losses can or improve roads, which is expensive, or improve the car's suspension, which is even more expensive, but in terms of thousands of cars is cheaper.
All the same road with a smooth surface impose the suspension is very strict. After all, speed is constantly increasing, and the requirements for handling and stability of automobiles and trains harder. Placing three-section pnevmoelement.
in equalizing rear axle car Tatra-815
Analysis of the design of the car shows that the weighting of the vehicle determined by the ratio of the payload to the weight of itself, is constantly growing. The desire for minimum curb weight, increase the weight coefficient of the vehicle and wearing comfort leads to the fact that the suspension with steel springs not
always able to fit into the requirements for them. In many cases, the suspension should:
- The maximum smoothness without significant mutual displacements sprung and unsprung parts of the car;
- The minimum clearance between the body (chassis) and axles;
- Constant height of a step or floor level when the load changes.
If the linear characteristics of the traditional elastic elements can not achieve acceptable natural frequency equal to 90-120 min-1, forcing designers to contact with non-linear elastic elements, progressive characteristic: Pneumatic and hydro-pneumatic, has a number of advantages.
First, these elastic elements have more energy in the main working range and large deflections, and hence, reducing the amplitude of the oscillations, reducing the amount of energy absorbed shocks, facilitate adjustment. In the suspensions with steel elastic elements and performance density is achieved only through a strong design complexity.
The second advantage - the ease of automatic control and dynamic stiffness of the suspension in accordance with the load, which allows you to get a great ride and improve the performance of the other. For the same size Suspension allows you to have a high degree of commonality for different duty vehicles with a significant difference in the magnitude of the sprung mass. This is the third advantage. Fourth, pnevmoelementy have extremely long life, unattainable for steel elastic elements. Such as cylinders buses GMC nursed to 1 million miles.
Permanent position of the body facilitates ensuring the correct kinematic suspension and steering actuator lowers the center of gravity of the car and, therefore, increase its stability. At any load provided proper position lights for safer night driving. It - five. Sixth, to improve vehicle stability when braking on air suspension often given another function: just adjust the braking forces at the wheels depending on the load changes on them.
Modern suspension (cargo) of the vehicle consists of three main components:
1. Elastic elements, which receive dynamic loads between the body or frame vehicle and road.
2. Elements, absorbing vibration suspension.
3. Node is responsible for stabilizing the vehicle relative to the plane of the road.
At this point in trucks, a variety of vehicle suspension design and engineering of the elastic elements. First of all, it yourself car tires, which efficiently absorb minor road irregularities. The larger wheels and lower the pressure in it, the greater the obstacle car crossed without much impact on the load frame. Heavy dump trucks with their huge wheels do without additional suspension components, as their tires effectively dampen road roughness. Slow wheel tractors and machinery in the form of an elastic element content with only air in the tires.
Second in age and frequency of use in modern technology elastic elements are springs. They come in different model, have a different production technology, but they are the most massively used in modern trucks, and they can be seen as a long-haul tractor, and on construction equipment, urban retail delivery vehicles, military trucks and racing. If previously installed on trucks thick packets korotkolistovyh springs, on modern machines have significantly reduced the number of springs, up to one-on some models, and the length increased, which improved the ride and reduced structural weight. If European manufacturers prefer long spring, their colleagues in the U.S. soon. Therefore trucks with the North American continent tougher on the go.
Air suspension widespread in Europe and the U.S. was 30-40 years ago. Its main advantage over the spring in the lower weight, it supplies more cheaply, and the truck has a better ride. Factory price of the truck with air suspension is higher than the machine with a spring, but the replacement pads in operation for less than the whole spring. In addition, trucks with air suspension smaller break asphalt roads, so most long-haul trucks are equipped with bellows. Disadvantage of this suspension is that it requires additional air valves and tubes and more powerful air compressor. This system is afraid of water and the mud, so the construction techniques used cup spring suspension. However, there is the Dutch manufacturer of heavy construction equipment and Terberg Ginaf, which are actively used air suspension of his own design for trucks.
Air bags do not have a rigid connection to the frame of the truck, and that the bridge does not "walk" in the design of the vehicle suspension used longitudinal and transverse thrust. This also complicates and increases the cost of construction.
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| Air Suspension |
