Kubota M108S, Руководство по ремонту, Страница: 96 / 523

1-M1
M108S, WSM ENGINE
1. FEATURE
The diesel engines have the feature of low cost and
high efficiency. On the other hand, it is said that an
amount of the nitrogen oxide (NOx) and particulate
matter (PM) contained in their exhaust gas is relatively
large, and the emission regulation by the EPA
(Environmental Protection Agency) has been gradually
strengthened in North America recently. Kubota, which
has been positively engaging in the strict emission
regulations of the world, has developed the new engine
conforming to the regulation of the EPA Tier III that
becomes effective since January 2007, by adopting the
CRS (Common Rail System) and the EGR (Exhaust Gas
Recirculation) in the course of pursuing more clean
exhaust gas.
The common rail system uses a type of accumulation
chamber called a rail to store pressurized fuel, and
injectors that contain electronically controlled solenoid
valves to inject the pressurized fuel into the cylinders.
Because the engine ECU (Electronic Control Unit)
controls the injection system (including the injection
pressure, injection rate, and injection timing), the
injection system is independent and thus unaffected by
the engine speed or load.
Because the engine ECU can control injection
quantity and timing to a high level of precision, even
multi-injection (multiple fuel injections in one injection
stroke) is possible.
This ensures a stable injection pressure at all times,
even in the low engine speed range, and dramatically
decreases the amount of black smoke ordinarily emitted
by a diesel engine during start-up and acceleration.
As a result, exhaust gas emissions are cleaner and
reduced, and higher power output is achieved.
W1012645
KiSC issued 06, 2007 A