Inyección directa Common-rail - parte 1

Evolution and Revolutions of Diesel Engines

Overview of Diesel Engine Development

• The title for a movie about the diesel engine's journey over the last decade could be "Evolution and Revolutions."

• Advances in combustion chamber design and new injection systems have improved performance while reducing harmful emissions.

Injection Systems in Diesel Engines

• Diesel engines are primarily differentiated by their fuel injection methods: indirect injection (in pre-chambers) versus direct injection (in combustion chambers).

• Direct injection technology has accelerated advancements in diesel engines, despite some drawbacks like vibrations and noise, limiting its use mainly to transport vehicles and machinery.

Key Components of Diesel Engines

• A crucial element is the injector pump, which has evolved significantly to enhance performance while maintaining its basic operational principles.

• Most modern diesel engines utilize electronic management systems; however, the common rail injection system represents a significant technological revolution.

Common Rail Injection System Functionality

• The common rail system operates similarly to gasoline electronic injection systems, where injectors receive fuel from a shared rail and are electrically actuated.

• The fuel circuit can be divided into three parts: low-pressure supply circuit, high-pressure circuit, and return circuit.

Low Pressure Supply Circuit Details

• The low-pressure supply circuit provides necessary fuel to the high-pressure pump using an electric pump and filter.

• This electric pump operates at 12 volts and includes roller-type volumetric designs with both check valves and safety features.

Fuel Pressure Regulation Mechanism

• The filter not only cleans but also regulates low pressure by controlling flow back to the tank when pressure exceeds spring control levels.

• A thermostatic element manages heating; if fuel temperature drops below 10 degrees Celsius, it redirects flow to a heater.

High Pressure Circuit Operation

• In the high-pressure circuit, the pump generates necessary flow rates without needing distribution calipers unlike conventional pumps.

• This section describes how pistons within the pump operate through eccentric motion driven by timing belts.