There is an urgent need for information on the development of automobile engines, and use it to do POWERPOINT teaching homework, four questions!

Today, the engine has reached a nearly perfect state. Throughout its growth history, it has almost been spent in the struggle of power, economy and environmental protection, but it is still so persistent that it is still absorbing new technologies, such as V-type technology, EFI technology, direct injection technology, VETC variable intake valve technology, variable intake manifold technology, ValveTronic valve control technology and turbocharging technology.

Maybe one day, the speed of a car is really as fast as the wind, but it may also be as unpredictable as the wind. Modern technology has really given people too much. When you are immersed in the pleasure and emotion brought by acceleration and high speed, maybe you really can't believe that the engine is just a device of a car, which actually contains so many high and new technologies.

Displacement related

V-technology: refers to the application of V-engine. At first glance, it is not complicated, perhaps a little concise, but its abundant power and absolute balance are unparalleled. It was born in the challenge of in-line L-type engine. On the one hand, people constantly demand to increase engine displacement and improve engine power, on the other hand, they constantly demand to reduce engine volume, reduce engine weight and improve engine stability. In this contradictory struggle, the L-type engine has been exhausted in Jiang Lang, and it can never meet this requirement, so the V-type engine appeared. From the original V6 to the present V 12, the V-type engine has reached an unprecedented peak. As you can imagine, the person who invented the V-engine is definitely a genius. From V6 to V 12, it should not be a simple digital superposition. Its process is far from 6+6 = 12. It is the crystallization of modern science and technology, which combines contemporary computer design technology, manufacturing technology, material technology and computer control technology. In the mid-1980s, even Mitsubishi Jeep. V 12 takes this V-shaped technology to the extreme. In fact, at present, only luxury car families such as Mercedes-Benz S600, BMW 760Li and Audi A86.0 have this technology, which is described by a widely circulated advertising word: V 12 is V 12. When you look at it, you may praise its fine processing, but don't forget that it is not a handicraft, but a practical guy.

EFI technology: It is a revolution in the engine field. You may have heard of the EFI technology of the engine, but it is still so strange to the public. In their eyes, the engine is the mechanical part of the car. In fact, as early as the 1960s, EFI technology began to appear. It is said that an industry elder got inspiration from an airplane engine. It was this inspiration that completely changed the fate of the engine. With the strong support of modern electronic technology, EFI technology has brought the power, economy and environmental protection of the engine to an almost perfect state, thus sending the traditional carburetor engine to the grave. Now there are EFI cars all over the street, so close to you, but it makes you feel strange. So what is EFI technology? Its basic principle is that the sensor senses the amount of air entering the engine, and the optimal fuel injection amount is determined by the accurate calculation of the engine computer, and then sprayed from the fuel nozzle and sent to the cylinder for combustion. It is such a process, but the power, economy and environmental protection of the engine have been improved unprecedentedly. According to the chemical combustion theory: 1kg gasoline needs 14.8kg air to burn completely in air, and the EFI technology can achieve this accurately. However, the combustion of engine mixture is much simpler than that of 65,438+0 kg gasoline and 65,438+04.8 kg air, and the required mixture ratio is different at different loads and speeds. No problem. EFI engines are always available. In fact, the original EFI engine only controlled the fuel injection quantity. Now the EFI engine not only controls the fuel injection quantity, but also controls the ignition, idle speed, emission and air conditioning, and even participates in the control of automatic gearbox, accelerated slip adjustment and electronic stability program control system, which perfectly embodies the modern electromechanical integration technology.

Direct injection technology: fuel is directly injected into the cylinder for combustion. A few years ago, direct injection technology was a myth in gasoline engines. Engine experts have found that if the lean gas combustion technology is applied to gasoline engines, the economy and power of the engines will be greatly improved. But there has been no better way, and the emergence of direct injection technology has undoubtedly brought dawn to solve this problem. The direct injection technology of gasoline engine is to install the injector in the cylinder like a spark plug, and use the principle of lean gas combustion to directly inject high-pressure gasoline into the cylinder for combustion, while the traditional EFI technology is to inject gasoline into the intake manifold and burn it in the cylinder through the intake valve. Extremely high fuel pressure and cylinder pressure ensure the realization of lean gas combustion. At present, this technology has been used in some gasoline engines. For example, BMW's latest top version 760Li adopts direct injection technology, which will undoubtedly become the development direction of future engines.

Related to intake efficiency

VETC variable intake valve technology: Changing the opening time of the intake valve through electronic control technology can improve the intake efficiency of the engine at some speed segments, thus improving the torque and power of the engine. According to the speed and load signals, the engine computer controls the variable intake valve solenoid valve to open or close the hydraulic system to change the camshaft angle. At present, many cars adopt this technology, such as Honda Accord, Volvo 80 and Audi A4. It's called VANOS on a BMW. Valvetronic valve control technology: This is a new technology exclusively adopted by BMW. The traditional way is that the accelerator pedal controls the throttle opening through cable to change the engine load, or the sensor sends a signal to the electronic throttle to control the throttle opening to change the engine load. Either way, at idle speed or under medium or small load, air intake will be blocked because of the small throttle opening, Val? Vetronic valve control technology boldly cancels the throttle control, and uses the valve controller to control the valve opening time and intake valve lift, which improves the intake air volume, reduces fuel consumption, and especially improves the torque characteristics of the engine in each speed range.

Variable intake manifold technology: adjust the length of intake manifold according to the engine speed, use long intake manifold to increase intake volume and torque at low speed, and use short intake manifold to increase intake volume and engine power at high speed. Its principle is that with the opening and closing of the intake valve, pressure fluctuation will occur in the intake pipe, forming suction wave and pressure wave, which will propagate at the speed of sound. The length of the intake pipe must be adjusted according to the engine speed to ensure the highest pressure wave before the intake valve closes. The engine computer controls the driving motor to adjust the opening of the manifold according to the speed signal, thus changing the length of the manifold.

These new technologies are enough for today's cars. As for the future of the engine, you can actually imagine it, or it may be as unpredictable as the wind. But one thing is certain, with the progress and development of the times, engine technology will be constantly updated, bringing people a qualitative leap.

Just like the celebrities in the legendary swordsman, they appeared at the most critical and urgent moment.