A Cummins fuel system, as described in the provided information, works by precisely delivering pressurized fuel directly into the engine's combustion chambers using an injection pump and unit injectors.
Key Components in this System
Based on the description, the fundamental components responsible for fuel delivery are:
- Injection Pump: This component takes fuel from the tank and increases its pressure significantly.
- Unit Injectors: These are located at each cylinder and receive the high-pressure fuel to spray it precisely into the combustion chamber.
The Fuel Injection Process
The operation follows a clear sequence to ensure fuel is delivered efficiently and at the right moment for combustion:
- Fuel is supplied to the injection pump.
- The injection pump pressurizes the fuel.
- The pump then delivers it to individual unit injectors.
- Each unit injector, in turn, precisely injects the fuel directly into each cylinder's combustion chamber.
This system ensures that the highly pressurized fuel is delivered directly into the cylinder where it is needed for combustion, managed by the unit injectors for timing and quantity.
The Role of the Injection Pump
The injection pump is critical as the first stage of high-pressure creation. It takes fuel and builds the necessary pressure required for effective atomization when the fuel is sprayed into the cylinder. It also acts as a distribution point, sending this pressurized fuel to the various unit injectors.
The Role of the Unit Injectors
Located within the cylinder head, the unit injectors are responsible for the final, crucial step. They receive the high-pressure fuel from the pump and precisely control the timing, duration, and pattern of the fuel spray directly into the combustion chamber. This precise injection is key to efficient and clean combustion in diesel engines.
This method, utilizing a separate injection pump and unit injectors, allows for robust pressure generation and fine control over the injection event at each cylinder.
