Side Exhaust Port System Rotary Engine
Seiji Tashima(Mazda Motor Corp.), Suguru@Fuse(Mazda
Motor Corp.), Ritsuharu Shimizu(Mazda Motor Corp.), Shinji Kanbara(Mazda
Motor Corp.), Shinya Ueki(Mazda Motor Corp.)
Structure of the side exhaust port system Rotary Engine
(RE) was theoretically expected to deliver low fuel consumption.
However, in order to address issues in production, the engine's internal
structure was modified and fuel system was changed. In addition, the
intake and exhaust systems were developed such that the engine would be
able to make most of the advantageous characteristics of the structure of
exhaust emissions and engine output. As a result, production of the
new generation RE was realized that satisfies both environmental
requirements and marketability. During the development of this
technology, compatibility with the hydrogen fuel was improved, which will
contribute to the future hydrogen society.
2. DESCRIPTION OF TECHNOLOGY
Previous RE had an issue with
combustion stability during idle operation. This drastically
restricted improvement of the fuel economy and exhaust gas, which was a
large roadblock to the evolution. The technologies described below
addressed this issue and evolved RE's major performances at the same time.
As Fig. 1 shows, previous RE used combination of the side intake port
and the peripheral exhaust port, which created overlap of the exhaust
stroke and the intake stroke. This caused poor combustion stability,
blocking improvement of the RE fuel economy. The newly developed
side exhaust port RE was geometrically able to avoid this overlap, but
still remained overlap with clearance on the rotor side face.
Therefore, cutoff seal was newly developed. The seal drastically
improved the major issue of combustion stability at idle operation,
delivering 20% of fuel economy improvement. The side exhaust port
also enabled reduction of the RE's largest exhaust emission of unburned
hydrocarbon by 30% and the increase of the intake port area by 30%.
Compact module variable intake mechanism was developed that carefully used
dynamic effects of intake air. This realized extremely high intake
charging efficiency at wide engine speed range, evolving to high density
@As a result of this development, improvement was made
to the engine's basic performances of fuel economy , exhaust emissions and
@The newly developed RE was introduced to the
Japanese market in April 2003 followed by the USA and European
markets. 57,480 units of RE had been produced as of the end of
December. It is likely that the RE will drastically exceed the
annual production plan of 60,000 units. Expectation of the new RE is
growing around the world.