As the hero behind the scenes of BOSCH (BOSCH), more than one hundred years, for the global auto industry contributed countless technology and invention, gradually grow into the world's largest automotive technology suppliers. Small make up take you to meet today from Bosch products - diesel high pressure common rail system, to see how it works.
In 1892, a German engineer Rudolf Diesel (Rudolf Diesel) invented the world's first Diesel engine, Diesel engine was named after his name Diesel. As we all know, many characteristics different from diesel gasoline, such as viscosity (including condition of dynamic viscosity and kinematic viscosity and viscosity), to stick some terms intuitive diesel gasoline; Light the way such as cylinders, gasoline USES the spark plug ignites, while diesel using compression. These characteristics of diesel is doomed to have to adopt the way of high pressure to make it burst of energy, so early diesel engine using high-pressure cylinders for the oil supply system provide a certain amount of stress.

The Bosch company, in 1927, for many years, the study of mechanical fuel pump into manufacturing, gradually, huge cylinder became a thing of the past.

Using traditional mechanical fuel pump diesel injection system driven by the camshaft, fuel injection pressure increased with the increase of engine speed and fuel injection quantity increased, the diesel system such as atomization effect is not stable, cold start difficulties and so on, also has been unable to meet increasingly stringent emission standards and reduce fuel consumption desire.

A subject to decades of precision electronic control diesel supply technology, through last century nineties by leaps and bounds in the electronic technology of dongfeng, finally completely applied in vehicle diesel engine, the technology is electronically controlled diesel high pressure common rail system. It higher injection pressure, atomization effect is better, more fuel-efficient and cleaner emissions. All this, without trial and error and efforts unceasingly for the Bosch company.

What is the high pressure common rail system

High pressure common rail system refers to the high pressure oil pump, pressure sensors and electronic control unit (ECU) of the closed loop system, the injection pressure and injection process completely separated from each other a way of oil supply, and before the camshaft drive of diesel fuel injection system is completely different. It is made of high pressure oil pump high pressure fuel to the fuel rail, through the oil pressure to achieve precise control for fuel rail, make the high-pressure tubing pressure size has nothing to do with the rotating speed of engine, can greatly reduce the pressure of diesel engine oil change with engine speed.
High pressure common rail system

Diesel high pressure common rail injection system consists of hydraulic system and electronic control system. The hydraulic system and low pressure hydraulic system and high-pressure hydraulic system. Low pressure hydraulic system includes a fuel tank, fuel pump, fuel filter, and low pressure oil pipe; High pressure hydraulic system consists of high pressure pump, high pressure oil rail, fuel injector and high-pressure tubing; Electronic Control system (Electronic Diesel Control, hereinafter referred to as EDC) including sensors, ECU (Electronic Control Unit, or ECU) and actuator (including fuel injector with solenoid valve, pressure Control valve, the preheating plug Control Unit, supercharging pressure regulator, egr regulator, throttle valve, etc.) and wiring harness.

Among them, injectors, high pressure pump, high pressure oil rail, electronic control unit for four core components of the diesel common rail system.

The fuel injector is atomized and distribution in the engine combustion chamber parts. Common rail injector fuel injection time and duration are given signal after precise electronic control unit (ECU), and is controlled by solenoid valves.
Is the role of high-pressure pump fuel by low voltage state by piston compresses it into high pressure state, in order to meet the system and the engine fuel injection pressure and injection quantity requirements.
The effect of high pressure oil rail is storage fuel, at the same time suppress because of high pressure oil pump and fuel injector fuel injection pressure fluctuations, to ensure that the system pressure is stable. High pressure oil rail for each cylinder all together, as a sign of common rail system.
Like engine electronic control unit (ECU) of the brain, it collects the operation parameters of engine, combined with stored calculation and processing characteristics of the map, and convey signals to the actuator, to achieve the operation of the engine control, fault diagnosis, etc.

The working principle of the high pressure common rail system

According to the acquisition of a variety of electronic control unit (ECU) real-time parameters (speed, throttle opening, rotating speed of the crankshaft and camshaft speed, fuel rail pressure, etc.) injection for the precise calculation of the current (fuel injection amount depends on the fuel rail pressure and the length of the solenoid valve open time), as the electromagnetic valve actuator and control opening and closing, diesel is ejected into the cylinder, to realize the current condition of optimal combustion.
High pressure common rail system can realize the stronger power, lower fuel consumption and cleaner emissions.