Analysis of the Principle of Engine Turbocharging-1

I believe everyone has experienced that when driving normally, the engine with "T" is very powerful. Why is the turbocharged engine so powerful? How is it supercharged? Let's learn about the working principle of the engine supercharger.

● The role of the throttle valve There are two main components in the engine intake system. One is the air filter, which is mainly responsible for filtering impurities in the air; the other is the intake pipe, which mainly introduces air into the cylinder. There is a very important component in the intake pipe, which is the throttle valve.

The main function of the throttle is to control the amount of mixed air entering the cylinder. So how does it control the intake volume? When we drive, the depth of the accelerator pedal is actually controlling the size of the throttle opening. The deeper the accelerator pedal is pressed, the larger the throttle opening, the larger the amount of mixed air entering, and the higher the engine speed.

The traditional cable throttle is connected to the accelerator pedal at one end and the throttle at the other end through a steel wire. Its transmission ratio is 1:1, and the control accuracy of this method is not ideal. The current electronic throttle (electronic throttle) transmits the force, amplitude and other data of the accelerator pedal action to the control unit for analysis through a position sensor, and then summarizes the driver's intention to step on the accelerator. The ECU then calculates the actual throttle opening and closing degree and issues instructions to control the throttle motor to achieve precise control of the throttle.

● The length of the intake manifold is variable? We usually see that the length of the intake manifold of the engine seems to be fixed. Can its length be changed? In fact, by installing a control valve in the intake manifold, the intake manifold can be divided into two sections by opening and closing it, thereby changing its effective length. So what is the purpose of changing the length of the intake manifold? It is mainly to improve the intake efficiency of the engine at different speeds, thereby improving the power performance of the engine at various speeds.

When the engine is running at a low speed, the black control valve is closed, and the airflow is forced to flow from the long manifold into the cylinder, which can increase the airflow speed and pressure of the intake, so that the gasoline and air are better mixed and the combustion is more complete (this is a bit like the principle that the water flow speed will become faster after squeezing a water pipe with a slow flow). When the engine speed increases, the control valve opens, and the airflow bypasses the lower end pipe and directly enters the cylinder. At this time, more air can be inhaled faster, increasing the intake volume of the engine at high speed.

● Why does the exhaust manifold have such a strange shape? The exhaust system of a car mainly includes the exhaust manifold, three-way catalytic converter, muffler and exhaust pipe, etc. Its main function is to discharge the exhaust gas burned in the cylinder into the atmosphere.

Why do most of the exhaust pipes we see have strange shapes? This design is mainly to minimize the interference or exhaust backflow of the exhaust gases from each cylinder, which would affect the engine's power performance.

Although the exhaust pipe is designed in a strange shape, in order to prevent turbulence, certain principles are still followed, such as the exhaust manifolds of each cylinder are as independent as possible and the lengths are as equal as possible; the exhaust manifold is as long as possible, etc.