High Pressure Common Rail Fuel System

High-Pressure Common Rail (HPCR) fuel system

A highly efficient fuel injection system is essential for the clean operation of a diesel engine. HPCR is an advanced fuel injection design that does a better job regulating fuel pressure and injection timing. HPCR is already being used on Bobcat’s high-output engines, and its Engine Control Unit (ECU) technology is instrumental in meeting Stage IIIB and Stage IV requirements.

It allows the application of further technologies such as Diesel Oxidation Catalyst (DOC), Selective Catalytic Reduction (SCR) and Diesel Particulate Filter (DPF) systems, which are described below.

How does HPCR work?

Fuel Pressure

• The high pressure pump applies high pressure to the fuel (1600 – 2400 bar)
• The Common Rail stores pressurised fuel
• The injectors deliver fuel to the engine

Injection Timing

The ECU (Engine Control Unit) controls the injectors precisely to allow multiple fuel injections during each combustion cycle.

The benefits of better combustion

High pressure transforms the fuel into an extremely fine mist as it leaves the injectors. The fuel combusts more thoroughly in this form, leading to:

• Lower fuel costs: as the fuel burns more completely, the engine needs less of it.
• Cleaner exhaust: less unburned fuel is emitted in the exhaust.
• Better performance: multiple injections during each combustion cycle make combustion last longer, creating more energy and more output from the engine.
• Increased comfort: longer-lasting combustion lowers peak engine cylinder pressure, which reduces engine noise levels, making operation more comfortable.