The use of supercharging technology to reduce engine displacement can balance the power and fuel economy of the car. This applies to both diesel and gasoline engines. Diesel engine boosting has long been commonplace, but gasoline engine boost is rare. The reasons are as follows: - Gasoline engine can easily reach higher power than turbocharged diesel engine even without boosting - Gasoline engine with exhaust gas turbocharged will have a negative impact on emissions - Gasoline engine boost is easy to cause knocking If the gasoline engine does not consider optimizing the fuel economy by shifting the operating point, then there is really no need to take pressure. However, in recent years, the fuel economy of gasoline engines has attracted more and more attention. At the same time, a considerable number of users have increasingly demanded the power of automobiles, so the supercharging of gasoline engines has attracted more and more attention. In order to fully exploit the potential of reducing displacement to improve the fuel economy of turbocharged gasoline engines, while controlling knocking without affecting emissions, the best solution is to use compression ratios that can change with operating conditions. In contrast, a naturally aspirated gasoline engine does not have a variable compression ratio; a diesel engine does not require a variable compression ratio at all. Variable compression ratio scheme comparison Figure 1 shows the principle of some basic schemes. Among them, the scheme (1) moves the cylinder and the cylinder head one position relative to the crankshaft, and the engine cylinder block "opens" the cover to a certain extent, so that the compression ratio can be changed, and has been implemented by SAAB company not long ago. Scheme (2) is similar, but with the aid of the secondary piston inside the cylinder head to change the volume of the combustion chamber. This construction has been implemented on a two-valve engine, but it is difficult to implement this solution on a four-valve cylinder head. Scheme (3) uses a compression-variable piston to change the compression ratio. Solution (4) bypasses this problem with an eccentric crank pin or a variable length link. The crankshaft of the solution (5) is supported on an eccentric, and the eccentric is rotated by an angle to change the position of the crankshaft in the vertical direction, so that the top dead center and the bottom dead center of the piston move simultaneously. One and the same amount. Since the crankshaft axis is displaced, the center line of the valve timing transmission chain and the power transmission chain are misaligned, so compensation must be made. The crankshaft of the solution (6) is also supported on an eccentric. Unlike the solution (5), it displaces the crankshaft by means of a rack instead of an eccentric. The schemes (7) to (9) achieve a variable compression ratio by means of a link divided into two sections and a lever is added. According to Table 1, only the variable shape of the combustion chamber interferes with the geometry of the combustion chamber to an unacceptable level, and other solutions do not significantly interfere with the geometry of the combustion chamber. Comparing the forces applied to the adjustment mechanism, the folding crankcase (active cylinder head and cylinder barrel) does not work well because the principle of the adjustment mechanism itself determines that it is in the force flow. In the case where the connecting rod is divided into two sections, the force is relatively favorable, but the eccentric shaft of the operating lever is subjected to a relatively large torque. The other options are better, and the variable piston (link) solution is better only when the gas and inertia forces are used to adjust the compression ratio and the system is automatically stable. Compound NPK Fertilizer,Compound Fertilizer NPK Granular,100 Water Soluble Fertilizer Compound Fertilizer Npk Granular,Water Soluble Fertilizer Co., Ltd. , http://www.qdnpkfertilizer.com
- Pressurization will lead to increased costs