Appeal 2007-0571
Application 10/277,004
FINDINGS OF FACT
The relevant facts include the following:
The goal of the invention is to provide improved EGR mass flow rate to the
intake manifold of an internal combustion engine (Specification 2:[0005]).
Appellants attain this goal by preventing backflow from the intake pipe or intake
manifold from entering either of the divided exhaust manifolds, thereby increasing
the use of the exhaust pulse energy (Specification 7:[0027]). Appellants further
attain this goal by preventing flow from one exhaust manifold entering the other
exhaust manifold when the pressure at one manifold is significantly lower than the
pressure at the other manifold, thereby further increasing the use of the exhaust
energy pulse (Specification 7:[0026]).
Bailey recognizes when utilizing EGR in a turbocharged engine, the
reintroduction of exhaust gases to the intake manifold will occur naturally when
the exhaust manifold pressure is higher than the turbocharged boost pressure.
However, when the turbocharged engine operates under low speed and high torque
conditions, the boost pressure is typically higher than the exhaust manifold
pressure and recirculation of the exhaust gases is not possible (Bailey, col. 1,
ll. 54-60). Bailey solves this problem by adding a one-way check valve in the
conduit between each exhaust manifold and the EGR system, as described below.
Bailey discloses an internal combustion engine 10 having an engine
block 11, a first exhaust manifold 14, a second exhaust manifold 16, a
turbocharger 18, an intake manifold 24, and an EGR system 26 (Bailey, col. 4,
ll. 1-6). Bailey discloses that the EGR system 26 includes a first check valve 64
6
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