Pump-line-nozzle
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The pump-line-nozzle system (unit pump, abbreviations PLD or UPS) is a diesel injection system for internal combustion engines. It was developed by Bosch for trucks in the 1990s . In this system, an individual injection pump actuated by the camshaft is assigned to each cylinder . The fuel is fed into the injection valve via a short line .
It resembles both an injection system made up of plug-in pumps and the pump-nozzle system .
The difference to the pump-nozzle is that the pump and injection nozzle are integrated in a housing without an intervening line, whereas the PLD system has a short line. This makes it easier to accommodate on the engine when the camshaft is not over the cylinder head, but leads to a low pressure loss.
The difference to the single pump is that the pump has an additional solenoid valve that can bridge the high pressure chamber of the pump to the low pressure area and thus variably shortens or interrupts the activation time compared to a purely cam-controlled system.
PLD systems have largely been replaced by common rail .
literature
- Robert Bosch GmbH: Diesel engine management. 4th edition, Vieweg, 2004, ISBN 3-528-23873-9 .