Yanmar EF-494T, Техническое руководство, Страница: 95 / 239

3 ENGINE 3 ENGINE
EF494T TM 06/2011 edition 87
<Emission control technology>
(3) :
The TNV engine features 2 intake valves and
2 exhaust valves per cylinder. The fuel direct-
injection valve is of vertical type and is center
located and the combustion chamber is located at
the center of the cylinder, thereby enabling a
decrease in emission of PM and NOx.
< Fuel technology >
(4) Intake and exhaust

Swirl ratio optimized by redesigning the intake
port

Air-fuel mixture optimized by reviewing the
compression ratio
Combustion chamber

Air-fuel mixture optimized by using a new
combustion chamber

Uniform injection achieved by reviewing the
nozzle mounting angle (locating it at the
center of the combustion chamber)
(A) Injection nozzle
(B) Combustion chamber
(C) Piston
Three new mechanisms of the MP4 pump
The mono-plunger type fuel pump uses a single plunger to distribute fuel uniformly to each cylinder,
thereby eliminating the variation in fuel distribution between the cylinders. Fuel is atomized by high-
pressure injection and the fuel timing at each engine speed and load condition is optimized by using a
revolution timer and a load timer. This has achieved clean exhaust and high-efficient combustion
performance.
The new TNV diesel engine ensures low fuel consumption and high eco-friendliness.