Operation4002−1/A1
Winterthur Gas & Diesel Ltd.
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3.8 Diesel Fuel Injection Control
3.8.1 Injection Valve Control
Each injection valve, related to the solenoid valve in each cylinder, is controlled
independently (see Fig. 9).
Usually, the three injection valves on each cylinder operate at the same time. Special
operation modes enable fuel injection with one, or the two injection valves, or with
multi-shot spray patterns.
To improve the spray at low load, one or two injection valves are cut out automatically
(see also 0280−1 Operation at Low Load).
The CCM-20 increases the control outputs up to the applicable signal level for the
injection control valves.
3.8.2 Injection Control
A higher current level (pull-in current) at the start of the injection is used to make sure
that the injector opens quickly (cycle-to-cycle). The lower current (hold-in current) is
set to on when the injector has opened. This lower current (and energy) level will
decrease the temperature in the CCM-20 driver circuit and the solenoid valve.
The fuel injection (see Fig. 9) is controlled as follows:
D The CCM-20 calculates the fuel injection quantity (injection period). The input
(specified as a Fuel Command), is related to the output from the speed controller.
D The related signal from the speed controller is changed into injection values.
These values give the duration of the fuel injection, i.e. the quantity of fuel
injected into each cylinder. This quantity is related to the engine load.
D If necessary, adjustments can be made for differences in the fuel supply to each
injector.
D The common rail pressure has an effect on the last injection timing values that
the engine control system uses. For the last injection timing process, each
CCM-20 receives accurate data about the angular position from the speed
sensors and crank angle sensors.
D The firing order and angular displacements of the cylinder are programmed in the
CCM-20. The engine control system uses different injection timing for each
cylinder to get the best operation results for all engine load ranges.
Engine Control System
2015-12
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