As the EA888, which is also well-known as the EA111 that matches the Volkswagen small-displacement model, is more advanced and younger in technology. The EA888 engine is a newly designed engine by Volkswagen. It combines a series of advanced technologies such as direct injection in the cylinder, turbocharged , and variable valve timing , achieving the combination of power and economical and environmental protection.
EA888 engine introduction
EA888 series engines include two displacements: 1.8TSI maximum power is 118kw (160PS)-5000-6200rpm, maximum torque is 250Nm-1500-4500rpm; 2.0TSI maximum power can reach 147kw (200PS)-5100-6000rpm, and 280Nm-1700-5000rpm. The mechanical structures of the two types of engines with displacement are basically the same. The difference is that the length of the connecting rods of crankshaft and piston is shortened by 2.0TSI than the connecting rods of 1.8TSI, and the crankshaft radius is increased to increase the exhaust volume. The piston top structures of the two are also different, mainly to adjust the working volume of combustion chamber , thereby ensuring a consistent compression ratio and achieving the same combustion effect. The 2.0TFSI (EA888) engine used on the Audi
model (such as A4L) is actually the same as the cylinder block and crankshaft of the 2.0TSI engine mentioned here. However, Audi uses its own technologies, such as AVS variable valve lift, controlled airflow and exhaust, etc. Therefore, the cylinder head, timing system and engine tuning will be different. It can be regarded as a high-end version of EA888.
The first batch of domestic EA888 series engines were equipped on the FAW-Volkswagen Magotan and Shanghai Volkswagen Octavia models. As one of Volkswagen's current main engines, the EA888 series engine is equipped with Volkswagen's CC, Sagitar , Tiguan, Passat , Octavia and other models. Technical characteristics of
EA888 engine:
1. Intake variable valve timing
EA888 engine adopts intake variable valve timing technology, which can effectively improve the intake and exhaust efficiency. Valve timing variable is achieved mainly through a vane hydraulic regulator located on the intake camshaft.
Blade regulator consists of an outer shell, an inner blade rotor and a locking pin located inside the blade rotor. The outer shell is fixed with the external timing gear and is driven by the crankshaft. The inner blade is directly fixed to the intake valve camshaft and rotates with it.
VVT-i variable valve timing working principle is to control the hydraulic press in the corresponding pipeline through the camshaft regulating valve to drive the blades in the regulator, and then drive the camshaft rotation, realizing the advance or delay of valve opening and closing, and the adjustable range reaches a crankshaft angle of 60°.
Direct injection system in cylinder
Fuel supply system is the most critical part of realizing direct injection in cylinder. To inject fuel into a cylinder with very high pressure, it must have sufficient injection pressure.
high-pressure fuel pump is a key link in fuel pressurization. EA888 engine's fuel pump is a simple structure single-plum pump driven by a four-sided (four-point) cam on the intake camshaft. The four-point cam can synchronize the oil supply stroke of the oil pump and the corresponding oil injection process of each cylinder, and the oil injection uniformity and repeatability of each cylinder are relatively good.
high-pressure fuel pump produces a maximum oil pressure of 150bar. According to the engine operating conditions, by adjusting the oil pressure control valve, the fuel pressure can be adjusted between 50bar-150bar. A 6-hole fuel injector is used, with a nozzle cone angle of 50°, which is more conducive to the full mixing of gasoline and air.
Water-cooled turbocharger technology
engine's turbocharger and exhaust pipe adopt an integrated design, which can reduce the volume and weight of excess parts to a certain extent, making this system relatively stable and reliable.
turbocharger cooling system, mainly transports coolant from the auxiliary cooler to the charge air cooler and exhaust gas turbocharger by the cooling circulation pump.It mainly includes two circulation channels. One is to cool the turbocharger system through the turbocharger; the other is to cool the charge air through the cooler in the intake manifold .
Intake manifold flip
By controlling the opening and closing of the intake manifold flip lip, it can meet the engine's inflation needs under different working conditions. If the engine is operating at a low speed, the lower intake passage can be closed through the intake manifold flip, which can reduce the cross-section of the air flow through to increase the air flow rate. Combined with the special design of the piston top, a strong intake vortex is effectively formed, which is conducive to the formation and atomization of the mixture.
Similarly, when the engine enters the high-speed operating condition and adopts a homogeneous mixed air mode, the intake manifold flips open the lower intake passage, increasing the cross-section of the air flow through to obtain more intake and increase the engine's output power.
variable displacement oil pump
In traditional oil pump work, as the engine speed increases, the pressure of oil continues to increase. The pressure of the oil is mainly limited by the pressure limiting valve inside the oil pump, but the oil book is still running at the maximum output, which not only consumes the engine's power, but also converts the input energy into heat energy, accelerating the aging of the oil.
EA888 engine uses a variable displacement oil pump, which mainly adjusts the oil pressure by adjusting the oil supply amount of the pump gear. It is mainly achieved by moving the two pump gears inside the oil pump relative to each other. The two pump gears have no displacement (facing opposite), and the oil supply capacity is the largest; the two pump gears have the largest displacement of (offset), and the oil supply is the smallest. It can further improve fuel economy and improve emissions. Because the engine oil pressure is high, the engine response load is large, and the fuel consumption will be large; and the previous design with higher oil pressure will also be more oil involved in the combustion, and the engine oil consumption will be large and the emissions will become worse.
Double counter-rotary balance shaft
EA888 engine adopts a double balance shaft, located on both sides of the lower end of the cylinder block, driven by the crankshaft and chain. The centrifugal force generated by the rotation of the two balance shafts itself is exactly the opposite direction of the centrifugal force generated by the crankshaft, which can offset most of the vibration, thereby enhancing the engine maneuver equilibrium state characteristics and reducing noise.
balance shaft is installed in a plastic tube so that it does not come into direct contact with the oil reflowed from the cylinder head to prevent and foam the oil.
Summary:
Volkswagen EA888 engine also combines advanced technologies such as direct injection in the cylinder, water-cooled turbocharger, variable valve timing, etc., and has lower fuel consumption, emissions and stronger power output. Compared with the EA111 1.4TSI engine, the EA888 engine adopts technologies such as dual balance shafts, valve ball rocker arm and power-starting integrated machine, making the engine run smoother and further reduce noise.
