Chapter
1 - (4’44”)
Environment and Energy: the indispensable evolution
of the automotive engine
In
order to remain competitive, car manufacturers must
produce vehicles with ever increasing levels of equipment,
performance, comfort and safety. It is, however, difficult
to manufacture vehicles that are both fuel-efficient
and powerful, and which conform to pollutant emissions
standards.
Even if Diesel engines are fuel-efficient, they emit
too much nitrogen oxides and after treatment solutions
have to be found quickly. On the other hand, gasoline
engines offer greater pollutants after treatment opportunities;
however, they are more fuel-consuming.
Therefore, both Diesel and gasoline engines must evolve
rapidly to respond to short-term environmental and energy
challenges while meeting market demands... But
in what context ? And at what price ?
Chapter
2 - (18’35”)
The Variable Compression Ratio: a decisive progress
Many
fundamental characteristics of IC engines depend on
their compression ratio: thermodynamic efficiency, pollutants
generation, knock limit, compatibility with fuels (octane
number), maximum supercharging pressure and exhaust
gases temperature.
Downsizing, Atkinson cycle, lean-burn combustion, Controlled
Auto Ignition, pollutant emissions control via cold
starting procedures... Variable Compression Ratio engines
will allow engine designers to satisfy essential requirements
for future engines. In the short term, Variable Compression
Ratio will make it possible to reconcile performance,
fuel efficiency and pollutants emissions reduction.
Chapter
3 - (13’06”)
Variable Compression Ratio engines: between compromise
and technical challenge
Controlling compression ratio involves controlling the
orientation or position of engine high loaded components:
moving parts, engine block, cylinder head… This
makes it difficult to design engines whose fundamental
features (such as piston kinematics, rigidity, mechanical
efficiency and overall size) are comparable or even
better than those of conventional engines.
Multi-link mechanisms, moving cylinder head, hydraulic
pistons, eccentric-mounted crankshafts or connecting
rods… Many different avenues of research have
been explored, each with its own advantages and drawbacks,
and with its own compromises.
Chapter
4 - (15’15”)
The MCE-5 technology
The
MCE-5 behaves as if it were a conventional engine with
a cylinder head gasket of variable thickness: its piston
kinematics remains identical to that of a conventional
engine whatever the compression ratio. The MCE-5 compression
ratio can be controlled from 6.7:1 to 17:1. Thanks to
its operational stability, the MCE-5 allows engine designers
to make the most of their know-how related to conventional
engines to design Variable Compression Ratio engines.
The innovative components of the MCE-5 are housed inside
a rigid and compact engine
block. Therefore, it can be integrated into all vehicles
just like any other conventional engine. Furthermore,
the MCE-5 provides numerous improvements: its roller-guided
piston is no longer subjected to slap or radial stress,
and its ultra-short crank radius makes its crankshaft
highly rigid.
Chapter
5 - (11’28”)
MCE-5: results and prospects
Four
years of intensive research have proven the technical
validity of the MCE-5. Studies involving more than 20
French SME’s have been supported by major manufacturers
and by French research programmes.
The MCE-5 has been tested for hundreds of hours under
high loads and using various lubricants - from the high
performance ones down to used oil - proving its robustness
and reliability. The next generation of the MCE-5 prototype,
which will conform to mass-production requirements,
is actually under development.
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