Unit Pump System (UPS)

The Unit Pump System (UPS) is a system for diesel direct injection. It is closely related to the Unit Injector System (UIS) and is exclusively available for commercial vehicles. Bosch was the world’s first manufacturer to market this technology, also known as the “Unit Pump System”, in 1995. The feature
of the UPS is that each engine cylinder has a unit pump
of its own. This consists of the high-pressure pump with integrated solenoid valve, a short injection fuel-injection
line, a pressure-delivery connection and a conventional nozzle-and-holder assembly.

The advantage of this system: it permits injection pressures of up to 2,200 bar. In addition, conversion from injection systems with traditional in-line or distributor fuel-injection pumps does not require complete redesign of the cylinder head. Engine manufacturers save development costs. A further advantage: damaged pump/valve units are simple to exchange.

The Unit Pump System particularly used in commercial vechile diesel engines with performance of up to 92 KW per cylinder and 4 to 18 cylinders.A second control unit is required if the number of cylinders exceeds eight.