What are the new technologies and structures of automobile engines? Their construction principle, technical advantages and application scope are briefly described.

In-cylinder direct injection technology, turbocharging technology, cVVT technology, VVH technology and EGR technology.

In-cylinder direct injection is also called FSI, and FSI (fuel stratified injection) fuel stratified injection technology represents a development direction of traditional gasoline engines. In the traditional gasoline engine, the cam position of the engine and various related working conditions are collected by the computer, and the injector is controlled to inject gasoline into the intake manifold. However, due to the distance between the nozzle and the combustion chamber, the mixing of gasoline and air is greatly influenced by the intake airflow and the valve switch, and tiny oil particles will be adsorbed on the pipeline wall, so it is hoped that the nozzle can directly inject fuel into the cylinder. FSI is an in-cylinder direct injection technology developed by Volkswagen Group to improve the shortcomings of traditional gasoline engines. The advanced direct injection gasoline engine adopts the fuel supply technology similar to that of diesel engine, and provides the required pressure above 100bar through the piston pump to provide gasoline for the electromagnetic injector located in the cylinder. Then the computer controls the fuel injector to directly inject the fuel into the combustion chamber at the most appropriate time, and the control accuracy is close to millisecond level. The key is to consider the installation of the injector and leave a certain space in the upper part of the cylinder. Because the Volkswagen 1.4TSI engine with extremely environmentally-friendly sparks has been arranged at the top of the cylinder.

The plug and the valves are already very compact, so they are arranged near the intake valve side. Due to the addition of ejector, the requirements for design and manufacture are quite high. If the layout is unreasonable, the manufacturing accuracy can not meet the requirements, and the stiffness is insufficient or even air leakage can only be lost. In addition, FSI engines require higher fuel quality. At present, the domestic oil consumption situation may be difficult to meet the requirements of FSI engines, so the imported golf of some FSI engines has become acclimatized. In addition, FSI technology adopts two different fuel injection modes, namely stratified fuel injection mode and uniform fuel injection mode. When the engine is running at low or medium speed, stratified injection mode is adopted. At this time, the throttle valve is in a half-open state, and air enters the cylinder from the intake pipe and collides with the top of the piston. Because the top of the piston is made into a special shape, the expected eddy current is formed near the spark plug. When the compression process draws to a close, a small amount of fuel is ejected by the fuel injector, forming combustible gas. This stratified fuel injection method can fully improve the economy of the engine, because at low speed and light load, only a mixture with high air content needs to be formed around the spark plug, and FSI makes it very close to the ideal state. When the throttle valve is fully open and the engine is running at high speed, a large amount of air enters the cylinder at high speed, forming a strong vortex and mixing evenly with gasoline. So as to promote the full combustion of fuel and improve the power output of the engine. The computer constantly changes the fuel injection mode according to the working condition of the engine, and always maintains the most suitable fuel supply mode. The full utilization of fuel not only improves fuel utilization efficiency and engine output power, but also improves emissions.

1, generally we call it popular, all say turbocharging, in fact, its realization is realized by turbocharger. The common understanding of turbocharger is air compressor, which increases the air intake by compressing air.

2. The turbocharger uses the inertia impulse of the exhaust gas discharged by the engine to drive the turbine in the turbine chamber, and the turbine drives the coaxial impeller to pressurize the air sent by the air cleaner pipeline into the cylinder. 3. When the engine speed increases (when accelerating), the exhaust gas discharge speed increases synchronously with the turbine speed, and the impeller compresses more air into the cylinder. With the increase of air pressure and density, more fuel can be burned, and the fuel quantity and engine speed can be increased accordingly, thus increasing the output power of the engine. 4. Under the existing technical conditions, the turbocharger is the only mechanical device that can increase the "output power" of the engine under the condition of "unchanged working efficiency". Generally, it can increase the engine output power 10% to about 40%. Then it can be inferred that if PassatB5/ 1.8 engine is used, the "output power" after adding turbocharger should be equivalent to the output power of 2.3L displacement engine. As you can imagine, this thing keeps the efficiency of the engine unchanged. With such a large machine, people can do more work, add a turbocharger to compress the air, expand the air intake, and thus increase the output power. It actually means overclocking the computer's CPU. Think about it, people are still very smart and the engine is not strong enough. Try to make it strong enough.

The working principle of CVVT is no different from that of VVTI, except that controlling valve timing has no function of controlling valve lift. Therefore, the engine will only change the time difference between intake and exhaust, but not the air intake. Simply put, its working principle is that when the engine changes from low speed to high speed, the electronic computer will automatically apply oil pressure to the small turbine in the driving gear of the intake camshaft, so that the small turbine rotates at a certain angle relative to the gear housing under the pressure, so that the camshaft rotates forward or backward within 60 degrees, thus changing the opening time of the intake valve and achieving the purpose of continuously adjusting the valve timing. Therefore, under the action of the above structure, it can ensure that the engine can change the valve opening and closing time according to different road conditions, and improve the fuel economy while ensuring sufficient traction output. CVVT system includes the following parts: oil pressure control valve, intake cam gear, crankshaft sensor, cam position sensor, oil pump and engine electronic control unit (ECU). The toothed disc of the air intake cam comprises an external gear driven by a timing belt, an internal gear connected with the air intake cam and a control piston which can move between the internal gear and the external gear. When the piston moves, the spiral gear on the piston will change the position of the external gear, thus changing the timing effect. The displacement of the piston is determined by the oil pressure control valve, which is an electronic control valve, and its oil pressure is controlled by the oil pump. When the computer (ECU) receives input signals such as engine speed, air intake, throttle position and engine temperature, it will determine the operation of the oil pressure control valve. The computer will also use the cam position sensor and crankshaft position sensor to determine the actual valve timing of the intake cam. When the engine is started or shut down, the position of the oil pressure control valve changes, so that the intake cam timing is in a delayed state. When the engine is idling or loading at low speed, the timing is also in the delayed position, which improves the stable working state of the engine. The intake cam is in the advanced position when it is in the middle position, and it is in the advanced angle position to increase the torque output when it is in the middle, low speed and high load. When at high speed, it is in a delayed position to facilitate high-speed operation. When the engine temperature is low, the cam position is in the delayed position, which stabilizes the idle speed and reduces the fuel consumption.