Internal-combustion engines – Poppet valve operating mechanism – Lubrication
Reexamination Certificate
1999-07-13
2001-04-10
Hoang, Tu Ba (Department: 3742)
Internal-combustion engines
Poppet valve operating mechanism
Lubrication
C123S19800E, C123S1950HC
Reexamination Certificate
active
06213074
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is generally directed toward internal combustion engines and, more specifically, to an internal combustion engine having a V-shaped engine block, wedge-shaped cylinder head and a single, integrated intake manifold and rocker cover.
2. Description of the Related Art
Internal combustion engines known in the related art may include, among other basic components, a cast engine block having a pair of cylinder banks arranged in a V-shaped configuration, a pair of cylinder heads associated with each cylinder bank mounted to the engine block and a pair of valve covers fastened to each cylinder head. Each bank of cylinders is usually serviced by a dedicated intake manifold mounted to each cylinder head. A plurality of pistons are reciprocated in cylinders formed in each cylinder bank of the engine block. Similarly, a plurality of valves supported in each cylinder head are opened and closed via rocker arms, cams or some other mechanism to provide fluid communication between the cylinders and intake and exhaust manifolds. Fuel is combusted within the cylinders to reciprocate the pistons which, in turn, act on a crankshaft from which power may be translated to drive an automotive vehicle or any number of other devices.
In the case of compression ignition or diesel engines, the fuel/air mixture is delivered at relatively high pressures via fuel injector assemblies. Presently, conventional injectors are delivering this mixture at pressures as high as 32,000 psi. These are fairly high pressures and have required considerable engineering attention to a number of engine components to ensure the structural integrity, good sealing properties and the effective atomization of the fuel within the combustion chamber.
In addition, modern, high speed, direct injection diesel engines often employ cylinder heads having four valves per cylinder to meet challenging performance, noise and emission targets. However, four-valve configurations typically present difficult packaging challenges for small bore, direct injection, diesel engines. As higher engine efficiencies are targeted, engine designers are pushing engines to achieve higher peak firing pressures, necessitating higher head bolt clamp loads. This requirement further complicates the cylinder head and intake port packaging approach.
Many diesel engines adapted for automotive applications in North America will require lower valve train costs to compete effectively with gasoline engines. This factor, among other things, has resulted in the use of an overhead valve (OHV) configuration in the cylinder head, rather than the more generally accepted single overhead camshaft (SOHC) or dual overhead cam shaft (DOHC) design. Especially when employed in connection with V-block engines, overhead valve configurations achieve the necessary automotive diesel-rated speeds with sufficient valve train stiffness, while at the same time resulting in lower overall costs. Further, overhead valve configurations reduce total friction when compared with single or double overhead cam configurations. However, engines which employ overhead valve configurations also require push rods to actuate the valve rocker. Push rods present an additional space claim in the already crowded cylinder head envelope.
In essence, then, the modem diesel engine must provide a substantial fuel economy advantage while meeting evermore stringent emission regulations which are imposed on smaller, more compact diesel engines. However, increasing demands for greater fuel economy, cleaner burning, fewer emissions, NO
x
and noise control in addition to better component packaging, have placed, and will continue to place, even higher demands on the engine. Thus, there is an ongoing need in the art for better control over these various parameters in a cost-effective manner.
SUMMARY OF THE INVENTION
The present invention overcomes these disadvantages in the related art in an internal combustion engine including an engine block having a pair of cylinder banks arranged in a V-shaped configuration. Each of the pair of cylinder banks presents a top wall disposed at an acute angle relative to the horizontal and plurality of cylinders disposed spaced from one another and longitudinally aligned within each cylinder bank. A pair of cylinder heads are associated with each pair of cylinder banks. Each of the cylinder heads includes upper and lower walls disposed at an angle relative to each other such that each cylinder head is substantially wedge-shaped in cross-section. The cylinder heads are mounted to the engine block such that the lower wall of each cylinder head seals the opposing top wall of the associated cylinder bank and closes the open ends of the cylinders and such that the upper wall of each cylinder head is substantially parallel to the horizontal. A pair of exhaust manifolds are mounted to each of the pair of cylinder heads. A single, integrated intake manifold and rocker cover is mounted to the horizontal upper walls of the cylinder heads. The integrated manifold and rocker cover provides intake air to the cylinders in each of the cylinder banks through the cylinder heads and recirculates exhaust gas from the exhaust manifold to each of the cylinders in the cylinder banks.
The present invention facilitates efficient engine component packing objectives by combining a single intake manifold for servicing both cylinder banks with a single rocker cover. Accordingly, the present invention eliminates the need for separate intake manifolds, gaskets, exhaust gas recirculation (EGR) cooler housings and certain on-board plumbing associated with externally mounted EGR valves. Further, the use of a wedge-shaped cylinder head design for a V-block engine provides a substantially horizontal mounting face for the single, integrated intake manifold and rocker cover. With this design, the intake manifold supplies intake air to the cylinders from above. Further, the wedge-shaped cylinder head provides vertical access into the intake port of the cylinder.
Accordingly, one advantage of the present invention is that it eliminates a number of components as well as plumbing, gaskets, brackets and fasteners associated with separate intake manifolds for each cylinder head, separate rocker covers and EGR cooling apparatuses.
Another advantage of the present invention is that the wedge-shaped cylinder heads present a substantially horizontal mounting surface for the intake manifold. This feature reduces stack up variability and avoids side loads on the cylinder head and block.
Still another advantage of the present invention is that the wedge-shaped cylinder heads provide added flexibility to optimize intake port geometry with a low loss top entry intake port. Further, vertical intake air entry into the cylinder head may be used to achieve additional tumble within the combustion chamber.
REFERENCES:
patent: 3949715 (1976-04-01), Faix et al.
patent: 3973548 (1976-08-01), Celli
patent: 4213440 (1980-07-01), Abe et al.
patent: 4257369 (1981-03-01), Abe et al.
patent: 4267812 (1981-05-01), Aula et al.
patent: 4471731 (1984-09-01), Kasting et al.
patent: 4601267 (1986-07-01), Kronich
patent: 5309885 (1994-05-01), Rawlings et al.
patent: 5323745 (1994-06-01), Sato et al.
patent: 6089199 (2000-07-01), Lohr et al.
patent: 6092498 (2000-07-01), Lohr et al.
patent: 6095105 (2000-08-01), Lohr et al.
patent: 6102014 (2000-08-01), Donaldson
Dahbour Fadi H.
Detroit Diesel Corporation
Hoang Tu Ba
Panagos Bill C.
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